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

Free Stargazing Weather Tonight

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

Georgetown

6.8000°N, 58.1700°W

Clear night

Clear skies — excellent for observing

Georgetown·6.8000, -58.1700

Tonight

Skip

46% cloud
watch dew
transparency n/a
no astro-dark window

Dew risk · low · Δ 4.8°C

Best viewing Tuesday

19:00–02:00 · good · 12% cloud · 86% RH

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

Cloud Cover

Visibility

28.3 km

Humidity

75%

Dew spread

4.8°C · Low dew risk

Temp

29°C

Wind

15 km/h

Cloud layers · Next 24h

Tonight avg 54%

LowMidHighAstro darkBest windowStack = low / mid / high cloud %

7-night outlook

Score · cloud · dew · dark

Best night this week: Sat · 53 (Maybe)

Tonight
42Skip
46% cloud
87% · moderate dew
No astro dark
Tomorrow
12Skip
92% cloud
95% · high dew
No astro dark
Tue
44Skip
19% cloud
89% · high dew
No astro dark
Wed
42Skip
25% cloud
92% · high dew
No astro dark
Thu
47Maybe
35% cloud
86% · moderate dew
No astro dark
Fri
24Skip
64% cloud
90% · high dew
No astro dark
Sat · best
53Maybe
23% cloud
87% · 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. Astronomical darkness uses local ephemerides. Check clouds and dew first, then Dark Sky Window for moonless hours.