From the National Oceanic & Atmospheric Administration (NOAA) press release:
Finding climate information, such as past weather conditions and temperature and precipitation averages and extremes, can be easily achieved through NOWData (NOAA Online Weather Data)—a tab click away on the newly-standardized climate pages of the 122 local NOAA National Weather Service forecast offices.
By visiting the NOAA National Weather Service's national climate Web portal, 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, users can access a wide range of climate products for nearly 3,900 locations. Daily 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.