OrbitaSkyEN · ES · PT
Astronomy Weather · An almanac

Will the sky be clear tonight?

Wednesday · 13 May 2026 · Palo Alto, California
Tonight's verdict
Excellent

Average cloud cover for the next twelve hours is just 0%. The sky should be wide open. Moon is 11% illuminated — factor that into deep-sky targets.

Cloud now
1%
Transparency
10/10
Seeing
7/10
Moon
11%
Next 24 hours
Hour-by-hour cloud cover. Amber = clear sky overhead. Times in your local zone.
182202061014
Clear sky
Cloud cover
About this forecast

Data source

Forecast hourly from Open-Meteo (free, no API key, refreshed every hour). Cloud cover is total opacity — low, mid, and high cloud combined. Updates every hour at the edge.

Transparency

Estimated 1–10 from cloud cover and humidity. Real transparency depends on aerosol load, smoke, and water vapor profile — none directly measured here. Treat as a relative ranking, not an absolute score.

Seeing

Estimated 1–10 from surface wind speed only. Actual seeing is governed by the jet stream and local atmospheric profile — surface wind is a coarse proxy. For high-resolution planetary work, cross-check with sites that model upper-atmospheric turbulence.