What is the sunniest state in the United States?

Florida.

Actually Florida is the fifth sunniest. According to USA today

The license plates proclaim Florida the Sunshine State, but the National Weather Service says five other states catch more rays. Arizona is No. 1, followed by California, Nevada, New Mexico and Texas, according to the weather service, which monitors about 265 weather stations nationwide

Florida has more days where between 20 to 70% of the sun is blocked by clouds than anywhere else in the continental United States, weather officials said. Weather experts said warm water surrounding the state, high humidity and a long rainy season make for cloudy skies.

Apalachicola, the sunniest spot in Florida, sees an average of 128 clear sunny days per year and Miami has 74. For comparison, Yuma, Ariz., has 242.

The Miami-Fort Lauderdale area averages 175 partly cloudy days per year and West Palm Beach, 159. Outside of Florida, the closest partly cloudy skies contender is Denver, with an average of 130.