Total Cloud Coverage

Total cloud coverage is the foundational weather parameter that defines lighting conditions for photography, measuring the percentage of sky obscured by clouds at all altitudes combined. Unlike layer-specific cloud measurements, total cloud coverage provides a single value indicating whether skies are clear (0-20%), partly cloudy (20-80%), or overcast (80-100%). For photographers, cloud coverage directly determines available light quantity, quality, and drama.

Clear skies below 10% offer harsh directional light during day and pristine dark skies for astrophotography at night, but provide little interest in the sky itself. Partly cloudy conditions from 30-70% create the most dynamic photography opportunities: broken clouds allow dramatic light rays, isolated clouds catch golden hour colors, and clearing storms reveal rainbows and dramatic skies. Overcast skies above 90% provide soft, even lighting ideal for forest photography, waterfalls, and portraits, eliminating harsh shadows but also removing sky interest and reducing color saturation.

Cloud coverage evolves throughout the day: morning low clouds often dissipate as sun warms the surface, midday heating builds cumulus clouds from 20% to 60%, and evening cooling may bring increasing high clouds. PhotoWeather tracks cloud coverage trends to alert photographers to clearing skies after frontal passage, building afternoon clouds for dramatic skies, and optimal coverage ranges for specific photography types. Understanding cloud coverage in combination with cloud altitude layers allows photographers to distinguish between low overcast that creates flat lighting from high thin clouds that enhance rather than obstruct golden hour light. Coastal regions often show morning overcast clearing to afternoon partial cloud cover, continental locations display afternoon cumulus buildup from morning clear skies, and frontal systems bring rapid cloud coverage changes from 0-100% within hours. For golden hour photography, target 30-60% coverage with clouds positioned to catch sunset colors. For Milky Way shots, seek coverage below 20%. For even outdoor portraits, embrace 80-100% overcast.