Sunshine is simply the direct beam of sunlight that reaches the ground when the sky is not obscured by clouds or thick haze. It is measured as the duration of bright sunshine or as the amount of energy received.

Hours of sunshine vary with latitude, season, and cloudiness. Deserts and high plateaus often record the highest annual totals. Sunshine duration is a basic climate statistic used in agriculture, tourism, and solar-energy planning.

Instruments called sunshine recorders or pyrheliometers quantify the resource. Beyond its practical value, sunshine affects human mood and vitamin D production. In weather observing, the presence or absence of sunshine helps characterize the day’s conditions.

• Direct sunlight reaching the surface
• Varies with location and cloud cover
• Measured for climate and energy use
• Influences health and daily life