diff --git a/src/main/java/ru/lconnected/patternexamples/behavioral/mediator/Mediator.java b/src/main/java/ru/lconnected/patternexamples/behavioral/mediator/Mediator.java
index ed2b331..a97800b 100644
--- a/src/main/java/ru/lconnected/patternexamples/behavioral/mediator/Mediator.java
+++ b/src/main/java/ru/lconnected/patternexamples/behavioral/mediator/Mediator.java
@@ -1,6 +1,8 @@
 package ru.lconnected.patternexamples.behavioral.mediator;
 
 /**
+ * Является посредником для взаимодействия нескольких объектов
+ * Уменьшает явную связь между ними
  * Created by lkhruschev on 11.11.2016.
  * lkhruschev@alvioneurope.ru
  * Skype: levasfx
diff --git a/src/main/java/ru/lconnected/patternexamples/behavioral/observer/Observable.java b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/Observable.java
new file mode 100644
index 0000000..f44f2a1
--- /dev/null
+++ b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/Observable.java
@@ -0,0 +1,15 @@
+package ru.lconnected.patternexamples.behavioral.observer;
+
+/**
+ * Делает класс наблюдаемым
+ * Created by lkhruschev on 11.11.2016.
+ * lkhruschev@alvioneurope.ru
+ * Skype: levasfx
+ */
+public interface Observable {
+
+    void registerObserver(Observer observer);
+    void removeObserver(Observer observer);
+    void notifyObservers();
+
+}
diff --git a/src/main/java/ru/lconnected/patternexamples/behavioral/observer/Observer.java b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/Observer.java
new file mode 100644
index 0000000..46bfa71
--- /dev/null
+++ b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/Observer.java
@@ -0,0 +1,13 @@
+package ru.lconnected.patternexamples.behavioral.observer;
+
+/**
+ * Описывает поведения наблюдателя, в данном случае для класса WeatherData
+ * Created by lkhruschev on 11.11.2016.
+ * lkhruschev@alvioneurope.ru
+ * Skype: levasfx
+ */
+public interface Observer {
+
+    void update(float temperature, float humidity, int pressure);
+
+}
\ No newline at end of file
diff --git a/src/main/java/ru/lconnected/patternexamples/behavioral/observer/TemperatureConverter.java b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/TemperatureConverter.java
new file mode 100644
index 0000000..635952d
--- /dev/null
+++ b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/TemperatureConverter.java
@@ -0,0 +1,26 @@
+package ru.lconnected.patternexamples.behavioral.observer;
+
+/**
+ * Created by lkhruschev on 11.11.2016.
+ * lkhruschev@alvioneurope.ru
+ * Skype: levasfx
+ */
+public class TemperatureConverter implements Observer {
+
+    private WeatherData weatherData;
+
+    public TemperatureConverter(WeatherData weatherData) {
+        this.weatherData = weatherData;
+        this.weatherData.registerObserver(this);
+    }
+
+    @Override
+    public void update(float temperature, float humidity, int pressure) {
+        System.out.println("[Temperature in fahrenheit] - " + convert(temperature));
+    }
+
+    private float convert(float temperature) {
+        return temperature * (9/5) + 32;
+    }
+
+}
diff --git a/src/main/java/ru/lconnected/patternexamples/behavioral/observer/WeatherData.java b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/WeatherData.java
new file mode 100644
index 0000000..cf07bdb
--- /dev/null
+++ b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/WeatherData.java
@@ -0,0 +1,46 @@
+package ru.lconnected.patternexamples.behavioral.observer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Created by lkhruschev on 11.11.2016.
+ * lkhruschev@alvioneurope.ru
+ * Skype: levasfx
+ */
+public class WeatherData implements Observable {
+
+    private List<Observer> observers;
+    private float temperature;
+    private float humidity;
+    private int pressure;
+
+    public WeatherData() {
+        observers = new ArrayList<>();
+    }
+
+    @Override
+    public void registerObserver(Observer observer) {
+        observers.add(observer);
+    }
+
+    @Override
+    public void removeObserver(Observer observer) {
+        observers.remove(observer);
+    }
+
+    @Override
+    public void notifyObservers() {
+        for (Observer observer : observers) {
+            observer.update(temperature, humidity, pressure);
+        }
+    }
+
+    public void setMeasurements(float temperature, float humidity, int pressure) {
+        this.temperature = temperature;
+        this.humidity = humidity;
+        this.pressure = pressure;
+        notifyObservers();
+    }
+
+}
diff --git a/src/main/java/ru/lconnected/patternexamples/behavioral/observer/WeatherDisplay.java b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/WeatherDisplay.java
new file mode 100644
index 0000000..94b0ca9
--- /dev/null
+++ b/src/main/java/ru/lconnected/patternexamples/behavioral/observer/WeatherDisplay.java
@@ -0,0 +1,34 @@
+package ru.lconnected.patternexamples.behavioral.observer;
+
+import java.util.Date;
+
+/**
+ * Created by lkhruschev on 11.11.2016.
+ * lkhruschev@alvioneurope.ru
+ * Skype: levasfx
+ */
+public class WeatherDisplay implements Observer {
+
+    private WeatherData weatherData;
+    private float temperature;
+    private float humidity;
+    private int pressure;
+
+    public WeatherDisplay(WeatherData weatherData) {
+        this.weatherData = weatherData;
+        this.weatherData.registerObserver(this);
+    }
+
+    @Override
+    public void update(float temperature, float humidity, int pressure) {
+        this.temperature = temperature;
+        this.humidity = humidity;
+        this.pressure = pressure;
+        display();
+    }
+
+    public void display() {
+        System.out.printf("["+new Date()+"] Сейчас значения:%.1f градусов цельсия и %.1f %% влажности. Давление %d мм рт. ст.\n", temperature, humidity, pressure);
+    }
+
+}
diff --git a/src/test/java/ru/lconnected/patternexamples/behavioral/observer/ObserverTest.java b/src/test/java/ru/lconnected/patternexamples/behavioral/observer/ObserverTest.java
new file mode 100644
index 0000000..3819a7d
--- /dev/null
+++ b/src/test/java/ru/lconnected/patternexamples/behavioral/observer/ObserverTest.java
@@ -0,0 +1,34 @@
+package ru.lconnected.patternexamples.behavioral.observer;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import static org.junit.Assert.*;
+
+/**
+ * Демонстрирует как классы WeatherDisplay и TemperatureConverter реагирую на события,
+ * происходящие в классе WeatherData
+ * Created by lkhruschev on 11.11.2016.
+ * lkhruschev@alvioneurope.ru
+ * Skype: levasfx
+ */
+public class ObserverTest {
+
+    private WeatherData weatherData;
+    private WeatherDisplay weatherDisplay;
+    private TemperatureConverter temperatureConverter;
+
+    @Before
+    public void setUp() {
+        weatherData = new WeatherData();
+        weatherDisplay = new WeatherDisplay(weatherData);
+        temperatureConverter = new TemperatureConverter(weatherData);
+    }
+
+    @Test
+    public void testUpdate() throws Exception {
+        weatherData.setMeasurements(29f, 65f, 745);
+        weatherData.setMeasurements(39f, 70f, 760);
+        weatherData.setMeasurements(42f, 72f, 763);
+    }
+}
\ No newline at end of file