Location data · North Rhine-Westphalia
Sun hours in Bonn
How sunny is Bonn? Over a year the sun delivers 1,307 kilowatt-hours onto every square metre here — in June roughly 4 times as much per day as in December. “Sun hours” has two meanings: the weather report counts how long the sun shines. For solar power what matters is how much energy arrives — and that is what this page shows, as peak sun hours (hours of full sun power).
For solar planning this means: an optimally tilted, south-facing array (35°) harvests an annual average of 3.58 peak sun hours per day in Bonn. In 9 out of 10 years at least 1,224 kWh/m² are reached. All values are computed from this location’s satellite hourly data, not estimated.
- Annual average (PSH)
- 3.58 kWh/m²/d
- P90 annual total
- 1,224 kWh/m²
- Optimal tilt
- 40°
- Terrain horizon max.
- 6.9°
Sun hours per month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PSH/day (35° south) | 1.42 | 2.41 | 3.61 | 4.86 | 5.08 | 5.43 | 5.26 | 4.81 | 4.24 | 2.83 | 1.72 | 1.24 |
| P90 | 1.08 | 1.73 | 2.81 | 4.11 | 4.39 | 4.48 | 4.59 | 4.14 | 3.78 | 2.43 | 1.42 | 0.97 |
Daily average per month in kWh/m² at 35° tilt, south-facing, including the terrain horizon of Bonn. P90 = reached in 9 out of 10 years.
Optimal tilt angle in Bonn
The annual optimum for Bonn is 40° south; anything between 25° and 52° counts as equivalent (below 2% difference). For winter operation (off-grid) 65° is optimal, for summer use 20°. Flat-laid modules lose 16.0 % versus the optimum. Adjusting twice a year would add 3.1 % here, monthly adjustment 4.1 % — only relevant for adjustable mounts.
Is a balcony solar kit worth it in Bonn?
A vertical south-facing railing in Bonn harvests 952 kWh/m² per year — 73 % of what an optimally tilted 35° panel yields at the same spot. December softens the penalty: with the low winter sun, the vertical plane reaches 118 % of the 35° December value, computed from the same hourly data with its own plane transposition. Open the balcony solar calculator with these coordinates →
Neighbouring places compared
- Troisdorf3.53 kWh/m²/d9 km
- Bad Neuenahr-Ahrweiler3.50 kWh/m²/d21 km
- Köln3.51 kWh/m²/d24 km