The National Climatic Data Center (NCDC), part of National Oceanic and Atmospheric Administration (NOAA), publishes The Climate Atlas of the United States. The latest edition is version 2.0, published in 2002.
The atlas is a great resource for climate maps of the entire United States, including Alaska and Hawaii. Users can map a wide range of climate data including temperature, precipitation, wind, pressure, mean percentage of visibility, and record maximum heating degree days, just to name a few of the many possibilities. The data are based on the period from 1961-1990.
Read more about the atlas on the Earth Sciences and Map Library blog.