What humidity is best for stargazing in Guyana?

Lower humidity and a wider temperature-to-dew-point spread reduce fog and dew risk. Tropical nights can still be usable, but saturated air often softens stars and wets optics faster than dry climates. This tool scores dew risk and prefers drier hours for the best window.

What does transparency mean here?

Transparency is estimated from CAMS aerosol optical depth via Open-Meteo’s open Air Quality API. It describes haze, not telescope seeing (arcsecond FWHM). Low AOD means a clearer line of sight.

Is this a replacement for a general weather app?

No — it filters forecast data for astronomy: cloud layer trends, humidity/dew risk, transparency, and when a usable dark window might open. Pair it with the Dark Sky Window tool for moonless darkness timing.

How far ahead should I check?

The 7-night outlook is for planning; treat tonight and tomorrow as the most reliable. Tropical convection can change quickly — refresh before you leave.

Tools

Is the Sky Clear Tonight? Free Forecast

Is tonight good for stargazing? Hourly cloud layers, dew risk, transparency, and a Go / Maybe / Skip score — so you know if tonight is worth the drive.

Georgetown

6.8000°N, 58.1700°W

Clear night

Maybe tonight — high dew risk

Georgetown·6.8000, -58.1700

Tonight

Maybe

17% cloud
high dew
transparency n/a
6.0h astro dark
moon 5% lit

Dew risk · low · Δ 5.8°C

Best viewing Thursday

19:00–05:00 · excellent · 9% cloud · 86% RH

Prefers clear, drier night hours inside astronomical darkness when available.

Current conditions

Cloud Cover

Visibility

48.5 km

Humidity

71%

Dew spread

5.8°C · Low dew risk

Temp

29°C

Wind

15 km/h

Cloud layers · Next 24h

Tonight avg 43%

LowMidHighAstro darkBest windowStack = low / mid / high cloud %

7-night outlook

Score · cloud · dew · dark

Best night this week: Thu · 72 (Go)

Tonight
61Maybe
17% cloud
90% · high dew
6h dark
Tomorrow
50Maybe
66% cloud
86% · moderate dew
6h dark
Wed
58Maybe
44% cloud
84% · moderate dew
6h dark
Thu · best
72Go
9% cloud
86% · moderate dew
6h dark
Fri
68Maybe
20% cloud
87% · moderate dew
6h dark
Sat
72Go
9% cloud
85% · moderate dew
5h dark
Sun
52Maybe
22% cloud
83% · moderate dew
No astro dark

Weather by Open-Meteo (CC BY 4.0). Transparency uses CAMS aerosol optical depth via Open-Meteo Air Quality — not telescope seeing (arcseconds).

Frequently asked questions

What humidity is best for stargazing in Guyana?: Lower humidity and a wider temperature-to-dew-point spread reduce fog and dew risk. Tropical nights can still be usable, but saturated air often softens stars and wets optics faster than dry climates. This tool scores dew risk and prefers drier hours for the best window.
What does transparency mean here?: Transparency is estimated from CAMS aerosol optical depth via Open-Meteo’s open Air Quality API. It describes haze, not telescope seeing (arcsecond FWHM). Low AOD means a clearer line of sight.
Is this a replacement for a general weather app?: No — it filters forecast data for astronomy: cloud layer trends, humidity/dew risk, transparency, and when a usable dark window might open. Pair it with the Dark Sky Window tool for moonless darkness timing.
How far ahead should I check?: The 7-night outlook is for planning; treat tonight and tomorrow as the most reliable. Tropical convection can change quickly — refresh before you leave.

Forecast and air-quality data by Open-Meteo (CC BY 4.0); aerosol fields from CAMS. Next: check your Bortle class, confirm moonless hours, then see what’s in the sky.