"Things You Wouldn't Know If We Didn't Blog Intermittently."
Boy, the map of the Atlantic Provinces really shows the truth of the old adage about Eastern Canada: Eight months of winter and four month of bad skiing!
So, if you want this data for the US, the National Renewable Energy Laboratory (NREL) is the place to go. They also have a link describing how the maps are made (what data is included, resolution, etc.)http://www.nrel.gov/gis/solar.htmlA technical term for it is "insolation" data and is a common reference in the design of solar collectors.
Holy cow! That's a lot of maps. Thanks, xcentric.
Don't forget, with all of that sunshine - high pressure systems - comes the bitter cold. I'll take a few more low pressures systems to get the moderate temperatures!