Solar resource
How much solar energy reaches the ground in 18 cities across the world this week, from Abuja to Houston. For any other country, open its profile for a forecast at the capital.
Seven-day outlook
Daily global horizontal irradiation, kWh/m². Darker cells mean more solar energy.
| City | Today | Wed | Thu | Fri | Sat | Sun | Mon | 7-day mean |
|---|---|---|---|---|---|---|---|---|
| Johannesburg | 7.8 | 4.1 | 7.2 | 6.4 | 6.8 | 7.1 | 7.3 | 6.67 |
| Kano | 6.1 | 6.1 | 6.3 | 6.3 | 6.4 | 6.3 | 6.2 | 6.24 |
| Nairobi | 7.8 | 7.3 | 5.9 | 5.5 | 5.0 | 5.1 | 6.3 | 6.14 |
| Lagos | 5.6 | 5.4 | 5.7 | 5.4 | 5.5 | 5.8 | 5.9 | 5.61 |
| Riyadh | 5.4 | 5.5 | 5.5 | 5.7 | 5.7 | 5.7 | 5.6 | 5.57 |
| São Paulo | 5.1 | 6.0 | 3.9 | 5.5 | 4.9 | 7.1 | 6.1 | 5.51 |
| Abuja | 5.3 | 4.5 | 5.5 | 5.8 | 6.1 | 5.6 | 5.5 | 5.47 |
| Sydney | 2.0 | 5.1 | 5.7 | 4.6 | 6.5 | 6.8 | 6.5 | 5.31 |
| Dubai | 4.8 | 4.9 | 5.0 | 5.6 | 5.5 | 5.6 | 5.6 | 5.27 |
| Houston | 5.2 | 3.9 | 5.4 | 5.4 | 5.3 | 5.3 | 3.8 | 4.90 |
| Cairo | 4.4 | 5.2 | 5.4 | 4.2 | 5.1 | 4.9 | 4.7 | 4.86 |
| New Delhi | 4.5 | 4.7 | 4.0 | 4.3 | 4.6 | 4.8 | 4.8 | 4.51 |
| Mexico City | 6.1 | 5.6 | 5.9 | 4.4 | 2.2 | 2.1 | 4.8 | 4.46 |
| Tokyo | 2.9 | 2.4 | 3.9 | 3.8 | 4.6 | 4.6 | 2.9 | 3.58 |
| Madrid | 4.4 | 4.4 | 4.4 | 4.1 | 1.9 | 2.2 | 2.6 | 3.43 |
| Beijing | 4.2 | 4.1 | 4.2 | 2.5 | 0.4 | 4.1 | 4.0 | 3.35 |
| London | 2.4 | 2.3 | 1.8 | 2.7 | 2.6 | 2.7 | 0.5 | 2.14 |
| Berlin | 2.5 | 2.2 | 2.1 | 2.8 | 1.1 | 1.5 | 2.1 | 2.03 |
Source: Open-Meteo, updated 13 Oct 2026. Modelled global horizontal irradiation from numerical weather forecasts, not ground-station measurements.
Reading these numbers
One kilowatt-hour per square metre is the solar energy falling on a flat square metre over a day. A typical modern panel converts around a fifth of that to electricity, before inverter and wiring losses.
Desert and dry-belt cities such as Riyadh, Dubai and Cairo usually receive the most; humid, cloudy and high-latitude cities the least, with strong seasonal swings. In West Africa, Harmattan dust can cut irradiation for days at a time.
These are model forecasts, not ground measurements. For bankable project design, use long-term satellite-derived datasets and on-site measurement.
