New in Wolfram Mathematica 7: Current & Historical Weather Data  previous | next 
Compare Climates in Different Cities
Mean temperature by month in Boston, MA and Miami, FL showing different temperatures and variabilities.
In[1]:=

Click for copyable input
DateListPlot[

 WeatherData[#, 

    "MeanTemperature", {{2000}, {2007}, "Month"}] & /@ {"KBOS", 

   "KMIA"}, Joined -> True, Filling -> Bottom]
Out[1]=