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Why halos appear
Sun-dogs and 22° halos come from hexagonal ice crystals in cirrus clouds, refracting sunlight at a fixed minimum angle.
Niche vertical · Amateur observation only
The toolkit for amateur sky watchers.
NimbusLab aggregates free, no-key, no-signup tools for cloud identification, atmospheric optics, meteorological calculation, and outdoor observation risk — built for hobbyists, not pilots.
Live snapshot
Global atmospheric pulse
Real-time averages computed across six observation cities via the free Open-Meteo API. Refreshes on every page load.
Avg temperature
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Avg wind
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Avg visibility
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Cloud cover
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Tool categories
Five focused tool families
Atmospheric Observation
Field tools for direct sky and atmosphere observation.
3 tools →
Cloud & Phenomena Identification
Identify clouds, halos, rainbows and rare optical events.
4 tools →
Meteorological Calculation
Convert and compute weather quantities offline.
4 tools →
Outdoor Weather Prediction
Plan amateur outings with risk-aware weather context.
1 tools →
Popular Science Query
Niche atmospheric science references and lookups.
7 tools →
Most used
Popular amateur tools
Cloud & Phenomena Identification
Cloud Type Identifier
Match an uploaded cloud photo against the 10 standard WMO cloud genera and read its meteorological meaning.
Open tool
Cloud & Phenomena Identification
Rainbow Formation Probability
Compute the chance of a primary rainbow forming right now from temperature, humidity, and solar altitude.
Open tool
Cloud & Phenomena Identification
Fog vs Haze Distinguisher
Tell meteorological fog from industrial haze using humidity, visibility, and dew-point spread.
Open tool
Cloud & Phenomena Identification
Thunderstorm Distance Calculator
Tap when you see the flash and again when you hear the thunder. The tool reports distance in km and miles.
Open tool
Atmospheric Observation
Observation Log Template Generator
Generate a printable amateur weather observation log with the fields professional networks use.
Open tool
Outdoor Weather Prediction
Outdoor Observation Risk Assessment
Score outdoor observation safety using current wind speed, precipitation, and visibility.
Open tool
Atmospheric Observation
Sun & Moon Angle Calculator
Compute solar altitude, azimuth, and moonlight angle for any place and time.
Open tool
Atmospheric Observation
Atmospheric Transparency Query
Estimate local atmospheric transparency for astronomical and meteorological observation.
Open tool
Science notes
Niche atmospheric knowledge
Curated short-reads on rare phenomena, amateur observation skills, and tool-usage tips. Updated periodically.
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Reading cumulus growth
Vertical growth before noon often signals afternoon storms — the atmosphere is unstable enough to feed the column.
3
Beaufort by smell
Veteran observers calibrate wind by leaf rustle and sea spray smell as much as anemometer readings.
Community
Observation cases from the field
Alpine ridge
Lenticular cloud chase, Dolomites
Used the cloud identifier and outdoor risk tool together to time a 4-hour window between gust fronts.
Coastal flat
Sea-fog vs haze, North Sea
Distinguisher correctly flagged a 96% RH bank as fog while the city app called it haze.
High desert
22° halo session, Atacama
Transparency index hit 9/10 — perfect window for cirrus refraction documentation.