The Guide
How sunset scores work
Every sunset and sunrise gets a single score from 0 to 100. Here's what that number means — and how we arrive at it.
Score Categories
Heavy cloud cover or fully overcast skies block the sun entirely. Little to no color at the horizon. Not worth planning around.
Low clouds block all light. The sun may not be visible at all.
Clear skies or sparse clouds. Some color may appear, but it's brief and muted. A pleasant evening but not a standout sunset.
Few or no clouds to reflect light. Color potential is limited.
A solid sunset with visible color. Mid-level clouds catch the light for several minutes. Worth stepping outside for.
Good cloud cover at the right altitude. Colors last for 10–20 minutes.
Vibrant colors across a wide expanse of sky. High clouds glow well after the sun dips below the horizon. A photographer's evening.
Optimal mid/high cloud cover. Rich oranges, pinks, and purples.
Exceptional conditions. The sky erupts in color for an extended duration — deep reds, purples, and golds spanning the horizon. Rare and spectacular.
All factors align: cloud height, coverage, and humidity. Colors last 30+ minutes.
How Predictions Work
Reyveil combines weather-model data — cloud cover, humidity, and atmospheric conditions — with solar geometry to predict sunset quality anywhere on Earth. The score is built from four factors:
Likely vibrancy based on cloud type and altitude
How much light reaches the clouds
Horizon obstruction from surrounding geography
Forecast reliability based on model agreement
Golden Hour
Golden hour is the period shortly after sunrise or before sunset when the sun is low on the horizon, producing warm, diffused light. It typically lasts 30–60 minutes depending on your latitude and season.
Reyveil shows the exact golden-hour window for your location alongside the quality score, so you know not just if the sky will be good, but when to be ready.