Demographics Atlas Open the interactive map →

Solar Radiation by County

Sunlight reaching the ground, averaged over the year, in kilowatt hours per square metre per day. This is what a solar panel has to work with. Measured on a one-degree grid, so it separates Arizona from Washington cleanly but not one county from its neighbour.

See Solar Radiation on the interactive map →

Highest counties

CountySolar Radiation
Yuma County, Arizona6.0
Imperial County, California5.9
Pima County, Arizona5.9
La Paz County, Arizona5.9
El Paso County, Texas5.9
Pinal County, Arizona5.9
Maricopa County, Arizona5.8
Cochise County, Arizona5.8
Santa Cruz County, Arizona5.8
San Bernardino County, California5.8
Hudspeth County, Texas5.8
Riverside County, California5.8

Lowest counties

CountySolar Radiation
Sitka City and Borough, Alaska2.3
Aleutians East Borough, Alaska2.3
Juneau City and Borough, Alaska2.4
Hoonah-Angoon Census Area, Alaska2.4
Haines Borough, Alaska2.4
Wrangell City and Borough, Alaska2.4
North Slope Borough, Alaska2.4
Ketchikan Gateway Borough, Alaska2.4
Prince of Wales-Hyder Census Area, Alaska2.5
Chugach Census Area, Alaska2.5
Kusilvak Census Area, Alaska2.5
Nome Census Area, Alaska2.5

Counted among: County land area