Solar irradiance measures how much solar energy reaches a surface (W/m²). Sunshine hours measure how long the sun is above a brightness threshold per year. GeoRank maps both — at 0.5° precision, calibrated against ground truth.
800 hr/yr → 3,500+ hr/yr
231,000+ calibrated data points. Pan globally, zoom to 0.5° cells. Three resolution tiers load automatically.
Open Interactive Map →Resolution & coverage
| Tier | Resolution | Cell size | Coverage | Data source | Loads at zoom |
|---|---|---|---|---|---|
| Global | 2.0° | ~220 km | Worldwide | NASA POWER + Ångström formula | 0–4 |
| Regional | 1.0° | ~110 km | Worldwide | NASA POWER interpolated | 5–7 |
| Local | 0.5° | ~55 km | Worldwide | ERA5 + IDW calibration | 8+ |
Color scale
The color scale runs from deep navy (lowest sunshine, ~800 hr/yr) through blue and orange to red (highest, 3,500+ hr/yr). Each cell represents one 0.5° × 0.5° grid square — approximately the size of a metropolitan area.
| Color | Range (hr/yr) | Example locations |
|---|---|---|
| Deep navy | 800–1,200 | Bergen, Reykjavik, Dublin |
| Blue | 1,200–1,600 | London, Amsterdam, Copenhagen |
| Mid blue | 1,600–2,000 | Paris, Berlin, Warsaw |
| Amber | 2,000–2,400 | Rome, Athens, Tbilisi |
| Orange | 2,400–2,800 | Lisbon, Barcelona, Cape Town |
| Deep orange | 2,800–3,200 | Algarve, Paphos, Las Palmas |
| Red | 3,200–3,500+ | Dubai, Phoenix, Aswan |
Global extremes
Common questions
Solar irradiance is the power per unit area received from the sun (measured in W/m²). It varies by latitude, season, cloud cover, and atmospheric conditions. GeoRank maps it as annual sunshine hours — the number of hours per year when solar irradiance exceeds 120 W/m², the standard WMO bright sunshine threshold.
For annual sunshine hours, the clearest winners are desert belt nations: UAE, Egypt, Morocco, Qatar, and Israel consistently rank highest in their respective regions. Within the continental US, Arizona and New Mexico top 3,800–4,000 hr/yr. Globally, the Sahara and Arabian Peninsula see the most consistent high irradiance.
Weather maps show real-time or short-term conditions. GeoRank shows calibrated annual averages — the long-run typical sunshine a location receives, not what's happening today. This is climate data, not weather data. It's built from 40+ years of ERA5 reanalysis corrected against 56 ground station observations.
Yes — the hr/day metric (average daily sunshine hours) is directly usable in solar PV yield calculations. A standard formula: Annual yield (kWh) ≈ Panel power (kW) × hr/day × 365 × system efficiency. For example: a 5kW system in Lisbon (7.8 hr/day) would yield approximately 5 × 7.8 × 365 × 0.8 ≈ 11,388 kWh/year before losses. See the methodology page for data precision details.
How ERA5 bias correction works, the IDW calibration approach, and the 56 reference stations used.
Read the methodology →