How the Sunshine Score works
One number, 0–100, for how good a destination's sunshine is in a given month. Computed the same way for every place on the atlas, from long-term climate normals — not forecasts.
The formula
For each destination and month we combine three ingredients:
- Warmth (about half the score) — the month's average daytime high. Full marks from 20 °C to 32 °C; nothing below 8 °C; fading above 32 °C until 42 °C scores zero. Pleasant sunshine, not just any sunshine.
- Dryness — the month's precipitation, scaled so 0 mm is perfect and 150 mm or more scores nothing. Wet season is cloud season, so this carries the seasonal sunshine signal.
- Sunniness — the destination's annual sunshine hours, scaled against 3,500 h/yr (about the sunniest places on Earth). Where sunshine data is missing we assume a neutral 2,000 h/yr.
Score = 100 × warmth × (0.5 + 0.5 × (0.55 × dryness + 0.45 × sunniness)). Warmth multiplies the whole score, so a freezing month scores zero no matter how clear the sky.
What the score is not
It is not a weather forecast, and it is deliberately opinionated: a 41 °C August scores low because standing in it is no fun, and a gloriously clear −5 °C ski morning scores zero because this is a sunshine atlas, not a snow one.
Data sources
- Monthly temperature and precipitation normals: CRU climatology (long-term gridded averages).
- Annual sunshine hours and rainy days: compiled climate normals per destination.
- Places, populations and coordinates: © GeoNames and OurAirports contributors.
- Photography via Wikimedia Commons.
Gridded climate normals can run a degree or two cool for coastal spots and don't capture microclimates — treat scores as a comparison tool, and the tables as long-term averages rather than guarantees.