SebastianK

This Plugin is very easy to handle. Just install with a few clicks and set it up in your configs. 
Then include it in your sidebar e.g. with the following code:
< ?php spWeatherShow(); ? > (without spaces)

spWeather

This Plugin gets the weather from google.de/google.com and shows the weather now and a 4 days forecast with tiny pics

enclick

Display the weather for your city on the sidebar. Select from various layouts, designs and colours
<ul>
<li>Select your country and city, check <a href="http://openweather.com" title="Weather round the world" rel="nofollow ugc">openweather.com</a> database of over 60,000 cities</li>
<li>Select from a range of small to large widget designs</li>
<li>Select centigrade or fahrenheit</li>
<li>Select custom text and backround colours</li>
<li>Examples of the weather widgets can be found at <a href="http://www.openweather.com/wordpress.phtml" title="wordpress weather plugins" rel="nofollow ugc">openweather.com/wordpress</a></li>
</ul>

My Weather

Display the weather for your city on the sidebar. Select from various layouts, designs and colours

spWeather vs My Weather