My two favourite maps of this week are both weather maps. WeatherSpark is a pretty amazing map that lets you view historical weather records and El Tiempo is a very good implementation of a Google Map to display weather forecasts.
WeatherSpark is a pretty amazing Google Map of current and historical weather conditions. The site lets you view the historical records of over 4,000 weather stations.
If you want to know what the weather was like in Honolulu on the day of Barack Obama's birth in August 1961 all you have to do is use the time-line to bring up the correct date and centre the map on Honolulu. You can then view the recorded weather for that day (a balmy 30 degrees centigrade).
If you are more interested in today's weather you can just centre the map on your location and view the current temperature and the current precipitation radar results.
Spanish newspaper El Mundo has created a very nice Google Map to show the weather in Spain.
The map's default view displays today's weather, however you can use the numbered icons at the top of the map to view the forecast for the next three days. If you click on any of the weather icons displayed on the map you can view today's weather at that location and view a quick three day forecast.