NOAA Historical Weather Data

NOAA (the National Oceanic and Atmospheric Administration) offers historical weather data from their climate website.

...users can click a desired location on a national map and be taken directly to the local climate page of the appropriate NOAA National Weather Service forecast office. Then, by clicking on the NOWData tab [far right]....past weather is available for the last two years with climate averages for the standard 30-year period of 1971-2000 and extremes for as long as a station has been taking observations.