This is the Average Peak Sunlight Hours by States. (Source: National Renewable Energy Laboratory NREL)
A ‘Peak Sunlight Hours’ is an hour in the day when the intensity of sunlight is at least 1,000 watts per square metre. Naturally, the amount of solar radiation (also known as ‘insolation’) increases each day towards noon, and then decreases again as the sun starts to set. The seasons will also determine how many peak sun-hours there are, with the summer (when the sun is highest in the sky) bringing the most, and winter bringing the least.