Mittelland-Route (Aachen – Zittau), stage 1: Aachen → Bonn
On stage 1 (Aachen → Bonn, 137 km) the best month is September: 78% of days were dry with highs of 10–30 °C, and riding Aachen → Bonn meant an average tailwind of 2.9 km/h (ERA5 2006–2025, 9:00–18:00).
← Mittelland-Route (Aachen – Zittau) (Whole route)
Weather by month
| Month | Good days | Rain days ≥ 1 mm | Rain, mm | Avg high | Days ≥ 30 °C | Days < 10 °C | Daylight, h |
|---|---|---|---|---|---|---|---|
| January | 6% | 29% | 73 | 5 °C | 0% | 88% | 8.4 † |
| February | 16% | 27% | 59 | 6 °C | 0% | 78% | 9.9 † |
| March | 39% | 27% | 62 | 10 °C | 0% | 53% | 11.7 |
| April | 64% | 23% | 48 | 14 °C | 0% | 22% | 13.7 |
| May | 67% | 31% | 77 | 18 °C | 0% | 3% | 15.5 |
| June | 68% | 29% | 77 | 21 °C | 4% | 0% | 16.5 |
| July | 63% | 30% | 85 | 23 °C | 9% | 0% | 16.1 |
| August | 62% | 31% | 87 | 23 °C | 8% | 0% | 14.5 |
| September | 78% | 21% | 62 | 19 °C | 1% | 0% | 12.5 |
| October | 67% | 24% | 67 | 14 °C | 0% | 13% | 10.6 † |
| November | 30% | 28% | 66 | 9 °C | 0% | 58% | 8.9 † |
| December | 10% | 28% | 76 | 6 °C | 0% | 83% | 8.0 † |
Best months are all months within 3 percentage points of the best one. † less than 11 hours of daylight — long stages get tight.
Wind by month
| Month | Wind Aachen → Bonn, km/h | Headwind > 15 km/h, Aachen → Bonn | Headwind > 15 km/h, Bonn → Aachen | Better way |
|---|---|---|---|---|
| January | +4.7 | 3% | 19% | Aachen → Bonn |
| February | +3.2 | 4% | 17% | Aachen → Bonn |
| March | +2.9 | 5% | 15% | Aachen → Bonn |
| April | +1.8 | 4% | 10% | either |
| May | +2.8 | 2% | 11% | Aachen → Bonn |
| June | +3.6 | 1% | 10% | Aachen → Bonn |
| July | +5.4 | 1% | 14% | Aachen → Bonn |
| August | +4.5 | 1% | 11% | Aachen → Bonn |
| September | +2.9 | 2% | 10% | Aachen → Bonn |
| October | +2.4 | 3% | 12% | Aachen → Bonn |
| November | +3.1 | 2% | 13% | Aachen → Bonn |
| December | +4.3 | 3% | 16% | Aachen → Bonn |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–25 | E | +4.2 |
| 25–51 | SE | +2.9 |
| 51–76 | SE | +1.6 |
| 76–101 | E | +3.7 |
| 101–126 | E | +3.0 |
| 126–137 | NW | +0.4 |
Other stages
- Aachen → Bonn 137 km
- Bonn → Siegen 131 km
- Siegen → Stadtallendorf 110 km
- Stadtallendorf → Heringen 116 km
- Heringen → Erfurt 118 km
- Erfurt → Gera 115 km
- Gera → Freiberg 124 km
- Freiberg → Neustadt in Sachsen 115 km
- Neustadt in Sachsen → Zittau 72 km
How to read the numbers
Wind is the 10 m wind of a 25-km grid cell, daytime hours 9:00–18:00 local solar time; at saddle height in a sheltered valley it is weaker, on a coast or ridge stronger. A positive value is a tailwind. ERA5 slightly over-counts days with ≥ 1 mm of rain (by about 5–7 percentage points) and underestimates daily highs by 1–2 °C. Good day = less than 1 mm of rain between 9:00 and 18:00 (riding hours, local solar time) and a high between 10 and 30 °C; rain at night or in the evening does not spoil it.