diff --git a/pom.xml b/pom.xml
index 6187768..9f06a86 100644
--- a/pom.xml
+++ b/pom.xml
@@ -35,10 +35,21 @@
     </properties>
 
     <dependencies>
+        <dependency>
+            <groupId>com.opencsv</groupId>
+            <artifactId>opencsv</artifactId>
+            <version>5.7.1</version>
+        </dependency>
         <dependency>
             <groupId>org.junit.jupiter</groupId>
             <artifactId>junit-jupiter-engine</artifactId>
-            <version>5.8.0-M1</version>
+            <version>5.9.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.junit.jupiter</groupId>
+            <artifactId>junit-jupiter-params</artifactId>
+            <version>5.9.0</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
diff --git a/src/main/java/de/bcxp/challenge/App.java b/src/main/java/de/bcxp/challenge/App.java
index a6c1150..2a62585 100644
--- a/src/main/java/de/bcxp/challenge/App.java
+++ b/src/main/java/de/bcxp/challenge/App.java
@@ -1,23 +1,47 @@
 package de.bcxp.challenge;
 
-/**
- * The entry class for your solution. This class is only aimed as starting point and not intended as baseline for your software
- * design. Read: create your own classes and packages as appropriate.
- */
+import de.bcxp.challenge.weather.data.DataSource;
+import de.bcxp.challenge.weather.data.WeatherDataSourceCSV;
+import de.bcxp.challenge.weather.data.WeatherRecord;
+import de.bcxp.challenge.weather.WeatherStatsApp;
+import de.bcxp.challenge.weather.ui.WeatherUi;
+import de.bcxp.challenge.weather.ui.WeatherUiCli;
+
+import java.io.FileNotFoundException;
+import java.nio.file.Path;
+
+
 public final class App {
 
+    private static final int EXIT_ERROR_DATA_WEATHER = 1;
+
     /**
-     * This is the main entry method of your program.
-     * @param args The CLI arguments passed
+     * The app's main entry point assembles all dependencies and injects them into the core modules.
+     * @param args CLI arguments, currently not used
      */
     public static void main(String... args) {
 
-        // Your preparation code …
+        Path csvWeather = Path.of("./src/main/resources/de/bcxp/challenge/weather.csv");
+        DataSource<WeatherRecord> weatherDataSource = tryInitWeatherDataSource(csvWeather);
+        WeatherUi weatherUi = new WeatherUiCli();
 
-        String dayWithSmallestTempSpread = "Someday";     // Your day analysis function call …
-        System.out.printf("Day with smallest temperature spread: %s%n", dayWithSmallestTempSpread);
+        WeatherStatsApp weatherStatsApp = new WeatherStatsApp(weatherDataSource, weatherUi);
+        weatherStatsApp.run();
 
         String countryWithHighestPopulationDensity = "Some country"; // Your population density analysis function call …
         System.out.printf("Country with highest population density: %s%n", countryWithHighestPopulationDensity);
     }
+
+    private static DataSource<WeatherRecord> tryInitWeatherDataSource(Path csvPath) {
+
+        try {
+            return new WeatherDataSourceCSV(csvPath);
+        } catch (FileNotFoundException e) {
+            System.out.printf("Error: CSV file for weather data not found: %s%n", csvPath);
+            System.exit(EXIT_ERROR_DATA_WEATHER);
+        }
+
+        return null;
+    }
+
 }
diff --git a/src/main/java/de/bcxp/challenge/weather/WeatherStatsApp.java b/src/main/java/de/bcxp/challenge/weather/WeatherStatsApp.java
new file mode 100644
index 0000000..2d631e7
--- /dev/null
+++ b/src/main/java/de/bcxp/challenge/weather/WeatherStatsApp.java
@@ -0,0 +1,38 @@
+package de.bcxp.challenge.weather;
+
+import de.bcxp.challenge.weather.data.DataSource;
+import de.bcxp.challenge.weather.data.WeatherRecord;
+import de.bcxp.challenge.weather.stats.WeatherStats;
+import de.bcxp.challenge.weather.ui.WeatherUi;
+
+
+public class WeatherStatsApp {
+
+    private final DataSource<WeatherRecord> dataSource;
+    private final WeatherUi weatherUi;
+
+    public WeatherStatsApp(DataSource<WeatherRecord> dataSource, WeatherUi weatherUi) {
+        this.dataSource = dataSource;
+        this.weatherUi = weatherUi;
+    }
+
+    /**
+     * Core business logic: Read data, calculate stats, display them.
+     */
+    public void run() {
+
+        try {
+
+            Iterable<WeatherRecord> data = this.dataSource.getData();
+            WeatherRecord minSpreadRecord = WeatherStats.findMinTemperatureSpread(data);
+            this.weatherUi.showMinTempSpread(minSpreadRecord);
+
+        } catch (Exception e) {
+            // There's not much error handling going on here. But this block is a good way to indicate that high-level
+            // error handling is part of the business logic and should probably go here.
+            System.out.printf("Error while calculating weather stats:%n%s%n", e);
+        }
+
+    }
+
+}
diff --git a/src/main/java/de/bcxp/challenge/weather/data/DataSource.java b/src/main/java/de/bcxp/challenge/weather/data/DataSource.java
new file mode 100644
index 0000000..98ae615
--- /dev/null
+++ b/src/main/java/de/bcxp/challenge/weather/data/DataSource.java
@@ -0,0 +1,6 @@
+package de.bcxp.challenge.weather.data;
+
+
+public interface DataSource<T> {
+    Iterable<T> getData();
+}
diff --git a/src/main/java/de/bcxp/challenge/weather/data/WeatherDataSourceCSV.java b/src/main/java/de/bcxp/challenge/weather/data/WeatherDataSourceCSV.java
new file mode 100644
index 0000000..eead0c5
--- /dev/null
+++ b/src/main/java/de/bcxp/challenge/weather/data/WeatherDataSourceCSV.java
@@ -0,0 +1,33 @@
+package de.bcxp.challenge.weather.data;
+
+import com.opencsv.bean.CsvToBeanBuilder;
+
+import java.io.FileNotFoundException;
+import java.io.FileReader;
+import java.nio.file.Path;
+
+public class WeatherDataSourceCSV implements DataSource<WeatherRecord> {
+
+    private final FileReader csvFileReader;
+
+    public WeatherDataSourceCSV(Path csvPath) throws FileNotFoundException {
+        // FileNotFoundException is an exception type that is clearly specific to a file-based implementation of the
+        // DataSource interface. Usually we should avoid throwing implementation-specific exceptions that are not
+        // defined by the interface. But for the constructor it's okay under the assumption that it will only be used in
+        // the main function in which the different dependencies are plugged together.
+        this.csvFileReader = new FileReader(csvPath.toString());
+    }
+
+    @Override
+    public Iterable<WeatherRecord> getData() {
+
+        CsvToBeanBuilder<WeatherRecord> beanBuilder = new CsvToBeanBuilder<>(this.csvFileReader);
+
+        return beanBuilder
+                .withOrderedResults(true)
+                .withType(WeatherRecord.class)
+                .build()
+                .parse();
+    }
+
+}
diff --git a/src/main/java/de/bcxp/challenge/weather/data/WeatherRecord.java b/src/main/java/de/bcxp/challenge/weather/data/WeatherRecord.java
new file mode 100644
index 0000000..aa59100
--- /dev/null
+++ b/src/main/java/de/bcxp/challenge/weather/data/WeatherRecord.java
@@ -0,0 +1,36 @@
+package de.bcxp.challenge.weather.data;
+
+import com.opencsv.bean.CsvBindByName;
+
+public class WeatherRecord {
+
+        @CsvBindByName(column = "Day", required = true)
+        private int day;
+
+        @CsvBindByName(column = "MxT", required = true)
+        private int mxt;
+
+        @CsvBindByName(column = "MnT", required = true)
+        private int mnt;
+
+        public WeatherRecord() {}  // openCSV needs this constructor when reading weather records from file
+
+        public WeatherRecord(int day, int mxt, int mnt) {
+                this.day = day;
+                this.mxt = mxt;
+                this.mnt = mnt;
+        }
+
+        public int getDay() {
+                return day;
+        }
+
+        public int getMxT() {
+                return mxt;
+        }
+
+        public int getMnT() {
+                return mnt;
+        }
+
+}
diff --git a/src/main/java/de/bcxp/challenge/weather/stats/WeatherStats.java b/src/main/java/de/bcxp/challenge/weather/stats/WeatherStats.java
new file mode 100644
index 0000000..ff02ef9
--- /dev/null
+++ b/src/main/java/de/bcxp/challenge/weather/stats/WeatherStats.java
@@ -0,0 +1,25 @@
+package de.bcxp.challenge.weather.stats;
+
+
+import de.bcxp.challenge.weather.data.WeatherRecord;
+
+import java.util.Comparator;
+import java.util.stream.Stream;
+import java.util.stream.StreamSupport;
+
+public class WeatherStats {
+
+    public static WeatherRecord findMinTemperatureSpread(Iterable<WeatherRecord> records) {
+
+        Stream<WeatherRecord> recordStream = StreamSupport.stream(records.spliterator(), false);
+
+        return recordStream
+                .min(Comparator.comparing(WeatherStats::getMinMaxSpread))
+                .orElse(null);
+    }
+
+    private static int getMinMaxSpread(WeatherRecord indexedRecord) {
+        return indexedRecord.getMxT() - indexedRecord.getMnT();
+    }
+
+}
diff --git a/src/main/java/de/bcxp/challenge/weather/ui/WeatherUi.java b/src/main/java/de/bcxp/challenge/weather/ui/WeatherUi.java
new file mode 100644
index 0000000..520ec79
--- /dev/null
+++ b/src/main/java/de/bcxp/challenge/weather/ui/WeatherUi.java
@@ -0,0 +1,10 @@
+package de.bcxp.challenge.weather.ui;
+
+
+import de.bcxp.challenge.weather.data.WeatherRecord;
+
+public interface WeatherUi {
+
+    void showMinTempSpread(WeatherRecord weatherRecord);
+
+}
diff --git a/src/main/java/de/bcxp/challenge/weather/ui/WeatherUiCli.java b/src/main/java/de/bcxp/challenge/weather/ui/WeatherUiCli.java
new file mode 100644
index 0000000..387b551
--- /dev/null
+++ b/src/main/java/de/bcxp/challenge/weather/ui/WeatherUiCli.java
@@ -0,0 +1,14 @@
+package de.bcxp.challenge.weather.ui;
+
+
+import de.bcxp.challenge.weather.data.WeatherRecord;
+
+public class WeatherUiCli implements WeatherUi {
+
+    @Override
+    public void showMinTempSpread(WeatherRecord minSpreadRecord) {
+        String minSpreadDay = minSpreadRecord != null ? String.valueOf(minSpreadRecord.getDay()) : "[N/A]";
+        System.out.printf("Day with smallest temperature spread: %s%n", minSpreadDay);
+    }
+
+}
diff --git a/src/test/java/de/bcxp/challenge/AppTest.java b/src/test/java/de/bcxp/challenge/AppTest.java
deleted file mode 100644
index e7b400c..0000000
--- a/src/test/java/de/bcxp/challenge/AppTest.java
+++ /dev/null
@@ -1,25 +0,0 @@
-package de.bcxp.challenge;
-
-import org.junit.jupiter.api.BeforeEach;
-import org.junit.jupiter.api.Test;
-
-import static org.junit.jupiter.api.Assertions.assertEquals;
-
-/**
- * Example JUnit 5 test case.
- */
-class AppTest {
-
-    private String successLabel = "not successful";
-
-    @BeforeEach
-    void setUp() {
-        successLabel = "successful";
-    }
-
-    @Test
-    void aPointlessTest() {
-        assertEquals("successful", successLabel, "My expectations were not met");
-    }
-
-}
\ No newline at end of file
diff --git a/src/test/java/de/bcxp/challenge/weather/WeatherDataSourceCsvTest.java b/src/test/java/de/bcxp/challenge/weather/WeatherDataSourceCsvTest.java
new file mode 100644
index 0000000..54c7948
--- /dev/null
+++ b/src/test/java/de/bcxp/challenge/weather/WeatherDataSourceCsvTest.java
@@ -0,0 +1,61 @@
+package de.bcxp.challenge.weather;
+
+import de.bcxp.challenge.weather.data.DataSource;
+import de.bcxp.challenge.weather.data.WeatherDataSourceCSV;
+import de.bcxp.challenge.weather.data.WeatherRecord;
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+import java.io.FileNotFoundException;
+import java.nio.file.Path;
+
+public class WeatherDataSourceCsvTest {
+
+    @Test
+    public void testInvalidPathThrowsException() {
+
+        // GIVEN an invalid path to CSV file
+        Path invalidPath = Path.of("./INVALID/PATH.csv");
+
+        // WHEN a CSV data source is instantiated with that path
+        // THEN a FileNotFoundException is thrown
+        Assertions.assertThrows(FileNotFoundException.class, () ->
+                new WeatherDataSourceCSV(invalidPath)
+        );
+
+    }
+
+
+    @Test
+    public void testEmptyCsvThrowsRuntimeException() throws FileNotFoundException {
+
+        // GIVEN a data source for an empty CSV file
+        Path csvPath = Path.of("./src/test/resources/challenge/weather_empty.csv");
+        DataSource<WeatherRecord> dataSource = new WeatherDataSourceCSV(csvPath);
+
+        // WHEN data is requested
+        // THEN an RuntimeException is thrown
+        Exception exception = Assertions.assertThrows(RuntimeException.class, () ->
+                dataSource.getData()
+        );
+
+        // AND the error message is descriptive
+        assert(exception.getMessage().contains("Error capturing CSV header"));
+    }
+
+
+    @Test
+    public void testUnexpectedFloatValuesThrowRuntimeException() throws FileNotFoundException {
+
+        // GIVEN a data source pointing to a CSV with float values instead of the expected integers
+        Path csvPath = Path.of("./src/test/resources/challenge/weather_with_float.csv");
+        DataSource<WeatherRecord> dataSource = new WeatherDataSourceCSV(csvPath);
+
+        // WHEN data is requested
+        // THEN an RuntimeException is thrown
+        Assertions.assertThrows(RuntimeException.class, () ->
+                dataSource.getData()
+        );
+    }
+
+}
diff --git a/src/test/java/de/bcxp/challenge/weather/WeatherDataSourceTest.java b/src/test/java/de/bcxp/challenge/weather/WeatherDataSourceTest.java
new file mode 100644
index 0000000..b05c8f2
--- /dev/null
+++ b/src/test/java/de/bcxp/challenge/weather/WeatherDataSourceTest.java
@@ -0,0 +1,60 @@
+package de.bcxp.challenge.weather;
+
+import de.bcxp.challenge.weather.data.DataSource;
+import de.bcxp.challenge.weather.data.WeatherRecord;
+import de.bcxp.challenge.weather.utils.WeatherDataSourceEnum;
+import de.bcxp.challenge.weather.utils.WeatherDataSourceFactory;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.EnumSource;
+
+import java.io.FileNotFoundException;
+import java.util.ArrayList;
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+
+
+public class WeatherDataSourceTest {
+
+    @ParameterizedTest
+    @EnumSource(WeatherDataSourceEnum.class)  // Run test for all DataSource implementations (as listed in the enum)
+    void testAllWeatherDataSourcesReturnPlausibleWeatherRecords(WeatherDataSourceEnum dataSourceEnum) throws FileNotFoundException {
+
+        // GIVEN a data source for weather records
+        DataSource<WeatherRecord> dataSource = WeatherDataSourceFactory.newInstance(dataSourceEnum);
+        assertNotNull(dataSource);
+
+        // WHEN data is read into a list
+        List<WeatherRecord> records = new ArrayList<>();
+        dataSource.getData().forEach(records::add);
+
+        // THEN there are three plausible weather records
+        for (int i = 0; i < 3; i++) {
+            WeatherRecord record = records.get(i);
+            assertEquals(i+1, record.getDay());
+            assert(record.getMxT() >= record.getMnT());
+        }
+
+    }
+
+    @ParameterizedTest
+    @EnumSource(WeatherDataSourceEnum.class)  // Run test for all DataSource implementations (as listed in the enum)
+    void testDataSourcesReturnKnownMockData(WeatherDataSourceEnum dataSourceEnum) throws FileNotFoundException {
+
+        // GIVEN a data source for weather records
+        DataSource<WeatherRecord> dataSource = WeatherDataSourceFactory.newInstance(dataSourceEnum);
+        assertNotNull(dataSource);
+
+        // WHEN data is read into a list
+        List<WeatherRecord> records = new ArrayList<>();
+        dataSource.getData().forEach(records::add);
+
+        // THEN the weather records contain expected values (regression test)
+        assertEquals(88, records.get(0).getMxT());
+        assertEquals(79, records.get(1).getMxT());
+        assertEquals(63, records.get(1).getMnT());
+        assertEquals(55, records.get(2).getMnT());
+    }
+
+}
diff --git a/src/test/java/de/bcxp/challenge/weather/WeatherStatsAppTest.java b/src/test/java/de/bcxp/challenge/weather/WeatherStatsAppTest.java
new file mode 100644
index 0000000..f3bacab
--- /dev/null
+++ b/src/test/java/de/bcxp/challenge/weather/WeatherStatsAppTest.java
@@ -0,0 +1,33 @@
+package de.bcxp.challenge.weather;
+
+
+import de.bcxp.challenge.weather.data.DataSource;
+import de.bcxp.challenge.weather.data.WeatherRecord;
+import de.bcxp.challenge.weather.stats.WeatherStats;
+import de.bcxp.challenge.weather.utils.WeatherDataSourceMock;
+import de.bcxp.challenge.weather.utils.WeatherUiMock;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+
+public class WeatherStatsAppTest {
+
+    @Test
+    void testAppDisplaysDayWithMinTempSpread() {
+
+        // GIVEN a WeatherStatsApp
+        DataSource<WeatherRecord> dataSource = new WeatherDataSourceMock(WeatherDataSourceMock.MOCK_RECORDS);
+        WeatherUiMock ui = new WeatherUiMock();
+        WeatherStatsApp app = new WeatherStatsApp(dataSource, ui);
+
+        // WHEN the app runs
+        app.run();
+
+        // THEN it "displays" the weather record with minimum spread
+        WeatherRecord expectedRecord = WeatherStats.findMinTemperatureSpread(dataSource.getData());
+        assertEquals(1, ui.shownRecords.size());
+        assertEquals(expectedRecord, ui.shownRecords.get(0));
+    }
+
+}
diff --git a/src/test/java/de/bcxp/challenge/weather/WeatherStatsTest.java b/src/test/java/de/bcxp/challenge/weather/WeatherStatsTest.java
new file mode 100644
index 0000000..827a66b
--- /dev/null
+++ b/src/test/java/de/bcxp/challenge/weather/WeatherStatsTest.java
@@ -0,0 +1,53 @@
+package de.bcxp.challenge.weather;
+
+
+import de.bcxp.challenge.weather.data.WeatherRecord;
+import de.bcxp.challenge.weather.stats.WeatherStats;
+import de.bcxp.challenge.weather.utils.WeatherDataSourceMock;
+import org.junit.jupiter.api.Test;
+
+import java.util.*;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+
+public class WeatherStatsTest {
+
+    @Test
+    void testMinSpreadForEmptyListIsNull() {
+
+        // GIVEN an empty list of weather records
+        Iterable<WeatherRecord> emptyRecords = new ArrayList<>();
+
+        // WHEN the record with minimum temperature spread is calculated
+        WeatherRecord minSpreadRecord = WeatherStats.findMinTemperatureSpread(emptyRecords);
+
+        // THEN the result is null
+        assertNull(minSpreadRecord);
+    }
+
+    @Test
+    void testMinimumTemperatureSpreadIsFound() {
+
+        // GIVEN weather records and their minimum temperature spread
+        List<WeatherRecord> records = WeatherDataSourceMock.MOCK_RECORDS;
+        WeatherRecord referenceMinSpreadRecord = records
+                .stream()
+                .min(
+                        Comparator.comparing(WeatherStatsTest::calcTemperatureSpread)
+                )
+                .orElse(null);
+
+        // WHEN the record with minimum temperature spread is calculated
+        WeatherRecord calculatedMinSpreadRecord = WeatherStats.findMinTemperatureSpread(records);
+
+        // THEN it corresponds to the reference minimum
+        assertNotNull(referenceMinSpreadRecord);
+        assertEquals(referenceMinSpreadRecord.getDay(), calculatedMinSpreadRecord.getDay());
+    }
+
+    private static int calcTemperatureSpread(WeatherRecord record) {
+        return record.getMxT() - record.getMnT();
+    }
+
+}
diff --git a/src/test/java/de/bcxp/challenge/weather/WeatherUiCliTest.java b/src/test/java/de/bcxp/challenge/weather/WeatherUiCliTest.java
new file mode 100644
index 0000000..9b47edd
--- /dev/null
+++ b/src/test/java/de/bcxp/challenge/weather/WeatherUiCliTest.java
@@ -0,0 +1,59 @@
+package de.bcxp.challenge.weather;
+
+
+import de.bcxp.challenge.weather.data.DataSource;
+import de.bcxp.challenge.weather.data.WeatherRecord;
+import de.bcxp.challenge.weather.ui.WeatherUi;
+import de.bcxp.challenge.weather.ui.WeatherUiCli;
+import de.bcxp.challenge.weather.utils.WeatherDataSourceMock;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.PrintStream;
+
+public class WeatherUiCliTest {
+
+    private final ByteArrayOutputStream outContent = new ByteArrayOutputStream();
+    private final PrintStream originalOut = System.out;
+
+    @BeforeEach
+    void setUpStreams() {
+        System.setOut(new PrintStream(outContent));
+    }
+
+    @AfterEach
+    public void restoreStreams() {
+        System.setOut(originalOut);
+    }
+
+    @Test
+    void testRecordIsPrinted() {
+
+        // GIVEN a CLI user interface and a weather record
+        WeatherUi ui = new WeatherUiCli();
+        DataSource<WeatherRecord> dataSource = new WeatherDataSourceMock(WeatherDataSourceMock.MOCK_RECORDS);
+        WeatherRecord record = dataSource.getData().iterator().next();
+
+        // WHEN the record is shown in the UI
+        ui.showMinTempSpread(record);
+
+        // THEN it is printed to (mocked) stdout
+        assert(outContent.toString().contains("Day with smallest temperature spread: 1"));
+    }
+
+    @Test
+    void testNullRecordIsPrinted() {
+
+        // GIVEN a CLI user interface and a weather record
+        WeatherUi ui = new WeatherUiCli();
+
+        // WHEN the record is shown in the UI
+        ui.showMinTempSpread(null);
+
+        // THEN it is printed to (mocked) stdout
+        assert(outContent.toString().contains("Day with smallest temperature spread: [N/A]"));
+    }
+
+}
diff --git a/src/test/java/de/bcxp/challenge/weather/utils/WeatherDataSourceEnum.java b/src/test/java/de/bcxp/challenge/weather/utils/WeatherDataSourceEnum.java
new file mode 100644
index 0000000..e488516
--- /dev/null
+++ b/src/test/java/de/bcxp/challenge/weather/utils/WeatherDataSourceEnum.java
@@ -0,0 +1,6 @@
+package de.bcxp.challenge.weather.utils;
+
+public enum WeatherDataSourceEnum {
+    MOCK,
+    CSV,
+}
diff --git a/src/test/java/de/bcxp/challenge/weather/utils/WeatherDataSourceFactory.java b/src/test/java/de/bcxp/challenge/weather/utils/WeatherDataSourceFactory.java
new file mode 100644
index 0000000..5863bdb
--- /dev/null
+++ b/src/test/java/de/bcxp/challenge/weather/utils/WeatherDataSourceFactory.java
@@ -0,0 +1,33 @@
+package de.bcxp.challenge.weather.utils;
+
+import de.bcxp.challenge.weather.data.DataSource;
+import de.bcxp.challenge.weather.data.WeatherDataSourceCSV;
+import de.bcxp.challenge.weather.data.WeatherRecord;
+
+import java.io.FileNotFoundException;
+import java.nio.file.Path;
+
+public class WeatherDataSourceFactory {
+
+    public static DataSource<WeatherRecord> newInstance(WeatherDataSourceEnum dataSourceEnum) throws FileNotFoundException {
+
+        if (dataSourceEnum == WeatherDataSourceEnum.MOCK) {
+            return newMock();
+        } else if (dataSourceEnum == WeatherDataSourceEnum.CSV) {
+            return newCsv();
+        }
+
+        return null;
+    }
+
+    private static DataSource<WeatherRecord> newMock() {
+        Iterable<WeatherRecord> records = WeatherDataSourceMock.MOCK_RECORDS;
+        return new WeatherDataSourceMock(records);
+    }
+
+    private static DataSource<WeatherRecord> newCsv() throws FileNotFoundException {
+        Path csvPath = Path.of("./src/test/resources/challenge/weather.csv");
+        return new WeatherDataSourceCSV(csvPath);
+    }
+
+}
diff --git a/src/test/java/de/bcxp/challenge/weather/utils/WeatherDataSourceMock.java b/src/test/java/de/bcxp/challenge/weather/utils/WeatherDataSourceMock.java
new file mode 100644
index 0000000..1b42daf
--- /dev/null
+++ b/src/test/java/de/bcxp/challenge/weather/utils/WeatherDataSourceMock.java
@@ -0,0 +1,29 @@
+package de.bcxp.challenge.weather.utils;
+
+
+import de.bcxp.challenge.weather.data.DataSource;
+import de.bcxp.challenge.weather.data.WeatherRecord;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class WeatherDataSourceMock implements DataSource<WeatherRecord> {
+
+    public static final List<WeatherRecord> MOCK_RECORDS = Arrays.asList(
+            new WeatherRecord(1, 88, 59),
+            new WeatherRecord(2, 79, 63),
+            new WeatherRecord(3, 77, 55)
+    );
+
+    private final Iterable<WeatherRecord> records;
+
+    public WeatherDataSourceMock(Iterable<WeatherRecord> mockRecords) {
+        this.records = mockRecords;
+    }
+
+    @Override
+    public Iterable<WeatherRecord> getData() {
+        return this.records;
+    }
+
+}
diff --git a/src/test/java/de/bcxp/challenge/weather/utils/WeatherUiMock.java b/src/test/java/de/bcxp/challenge/weather/utils/WeatherUiMock.java
new file mode 100644
index 0000000..aea87cd
--- /dev/null
+++ b/src/test/java/de/bcxp/challenge/weather/utils/WeatherUiMock.java
@@ -0,0 +1,20 @@
+package de.bcxp.challenge.weather.utils;
+
+
+import de.bcxp.challenge.weather.data.WeatherRecord;
+import de.bcxp.challenge.weather.ui.WeatherUi;
+
+import java.util.ArrayList;
+import java.util.List;
+
+
+public class WeatherUiMock implements WeatherUi {
+
+    public List<WeatherRecord> shownRecords = new ArrayList<>();
+
+    @Override
+    public void showMinTempSpread(WeatherRecord weatherRecord) {
+        this.shownRecords.add(weatherRecord);
+    }
+
+}
diff --git a/src/test/resources/challenge/weather.csv b/src/test/resources/challenge/weather.csv
new file mode 100644
index 0000000..2f6c771
--- /dev/null
+++ b/src/test/resources/challenge/weather.csv
@@ -0,0 +1,4 @@
+Day,MxT,MnT,AvT,AvDP,1HrP TPcpn,PDir,AvSp,Dir,MxS,SkyC,MxR,Mn,R AvSLP
+1,88,59,74,53.8,0,280,9.6,270,17,1.6,93,23,1004.5
+2,79,63,71,46.5,0,330,8.7,340,23,3.3,70,28,1004.5
+3,77,55,66,39.6,0,350,5,350,9,2.8,59,24,1016.8
\ No newline at end of file
diff --git a/src/test/resources/challenge/weather_empty.csv b/src/test/resources/challenge/weather_empty.csv
new file mode 100644
index 0000000..e69de29
diff --git a/src/test/resources/challenge/weather_with_float.csv b/src/test/resources/challenge/weather_with_float.csv
new file mode 100644
index 0000000..9c5af26
--- /dev/null
+++ b/src/test/resources/challenge/weather_with_float.csv
@@ -0,0 +1,4 @@
+Day,MxT,MnT,AvT,AvDP,1HrP TPcpn,PDir,AvSp,Dir,MxS,SkyC,MxR,Mn,R AvSLP
+1.1,8.8,5.9,74,53.8,0,280,9.6,270,17,1.6,93,23,1004.5
+2.0,7.9,6.3,71,46.5,0,330,8.7,340,23,3.3,70,28,1004.5
+3.0,7.7,5.5,66,39.6,0,350,5,350,9,2.8,59,24,1016.8
\ No newline at end of file

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