Sky RadarSky Radar — sunset burn & astrophotography forecast for Vietnam
Sky Radar (also written SkyRadar) is a free app (web + Android) that answers the one question every landscape and night-sky photographer in Vietnam asks before heading out: will the sky burn tonight — and where should I shoot? It scores every hour, at any point across all 63 provinces of Vietnam, from 0 to 100.
Open the web app Download for Android
Key features
- Burn score: the probability of a vivid, colorful sunset or sunrise. The algorithm analyses three cloud layers, visibility and PM2.5 aerosols, and scans for blocking clouds up to 300 km along the sun's bearing following the Earth's curvature — because a burning sky needs sunlight to reach the cloud base from below the horizon.
- Astro score: Milky Way and starscape conditions — cloud cover, transparency, Moon phase and altitude, galactic core position, and sky darkness on the Bortle scale.
- Dark-sky map: a VIIRS satellite light-pollution overlay plus nearly 50 curated dark-sky shooting locations across Vietnam with field notes.
- Spot scanner: automatically sweeps up to 500 km around you to find the best place and hour to shoot in the coming days.
- Virtual sky: a real-time planetarium for your exact location — stars, constellations, planets and the Milky Way band — so you can plan compositions before you go.
- Safety alerts: lightning, wind gusts, heavy rain and flooding — assessed specifically for someone standing outdoors with a camera and a drone.
How Sky Radar works
Sky Radar blends multiple global weather models (ECMWF, ICON, GFS, JMA) via Open-Meteo with air quality data, VIIRS night-light satellite imagery and lightpollutionmap.info. What makes it different: the scoring algorithm is continuously calibrated against real photographs taken in the field across Vietnam — every time a forecast misses, the formula is dissected and tuned against hard evidence.
Who builds Sky Radar?
Duy Chris — a Vietnamese landscape and astrophotographer with 35+ photography awards, and an IT engineer. Sky Radar grew out of a photographer's own frustration: generic weather apps can't answer "will the sky burn?", so he built a tool dedicated to chasing light in Vietnam's tropical climate.
Frequently asked questions
What is Sky Radar?
A free app (web + Android) forecasting photography conditions in Vietnam: sunset/sunrise burn, Milky Way and starscape shooting, a dark-sky map, and severe weather alerts.
What is a burn score?
A 0–100 forecast of how likely the sky will light up in color at a given place and hour — based on three cloud layers, visibility, aerosols, and cloud blocking along the sun's direction up to 300 km away.
What is an astro score?
A 0–100 forecast for Milky Way and night-sky shooting: clouds, transparency, the Moon, galactic core position and local sky darkness.
Is Sky Radar free?
Yes — core features are free with a 3-day forecast. Pro extends it to 7 days for longer trip planning.
Where do I download it?
Web: app.duychris.com. Android APK: download here. Google Play and iOS are coming soon.
How accurate is it?
No forecast is ever 100% right — Sky Radar reports probabilities with a confidence index for each forecast, and the algorithm is regularly recalibrated against real field photos from Vietnam's photography community.