Location data · North Rhine-Westphalia
Sun hours in Iserlohn
How sunny is Iserlohn? Over a year the sun delivers 1,268 kilowatt-hours onto every square metre here — in June roughly 5 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 3.47 peak sun hours per day in Iserlohn. In 9 out of 10 years at least 1,172 kWh/m² are reached. All values are computed from this location’s satellite hourly data, not estimated.
- Annual average (PSH)
- 3.47 kWh/m²/d
- P90 annual total
- 1,172 kWh/m²
- Optimal tilt
- 40°
- Terrain horizon max.
- 5.3°
Sun hours per month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PSH/day (35° south) | 1.26 | 2.21 | 3.50 | 4.71 | 5.06 | 5.33 | 5.15 | 4.78 | 4.04 | 2.79 | 1.71 | 1.08 |
| P90 | 0.97 | 1.57 | 2.71 | 3.79 | 4.34 | 4.53 | 4.66 | 4.22 | 3.40 | 2.12 | 1.21 | 0.74 |
Daily average per month in kWh/m² at 35° tilt, south-facing, including the terrain horizon of Iserlohn. P90 = reached in 9 out of 10 years.
Optimal tilt angle in Iserlohn
The annual optimum for Iserlohn is 40° south; anything between 24° and 51° counts as equivalent (below 2% difference). For winter operation (off-grid) 65° is optimal, for summer use 20°. Flat-laid modules lose 15.1 % versus the optimum. Adjusting twice a year would add 2.9 % here, monthly adjustment 4.0 % — only relevant for adjustable mounts.
Is a balcony solar kit worth it in Iserlohn?
A vertical south-facing railing in Iserlohn harvests 919 kWh/m² per year — 72 % 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 113 % 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
- Hagen3.33 kWh/m²/d16 km
- Lüdenscheid2.70 kWh/m²/d18 km
- Sundern3.31 kWh/m²/d22 km