Grünroute: which way and when to ride
The best month for Grünroute is September: 78% of days were dry with highs of 10–30 °C. In September, riding Paal → Düren meant an average tailwind of 2.2 km/h (ERA5 2006–2025, daytime 9:00–18:00).
Also passes through Germany, Belgium
Weather by month
| Month | Good days | Rain days ≥ 1 mm | Rain, mm | Avg high | Days ≥ 30 °C | Days < 10 °C | Daylight, h |
|---|---|---|---|---|---|---|---|
| January | 7% | 29% | 74 | 5 °C | 0% | 86% | 8.4 † |
| February | 17% | 27% | 62 | 7 °C | 0% | 75% | 9.9 † |
| March | 42% | 27% | 61 | 10 °C | 0% | 48% | 11.7 |
| April | 68% | 22% | 45 | 15 °C | 0% | 18% | 13.8 |
| May | 71% | 28% | 69 | 18 °C | 0% | 3% | 15.5 |
| June | 70% | 26% | 73 | 22 °C | 4% | 0% | 16.5 |
| July | 63% | 30% | 80 | 23 °C | 8% | 0% | 16.1 |
| August | 65% | 29% | 78 | 23 °C | 8% | 0% | 14.5 |
| September | 78% | 20% | 59 | 20 °C | 1% | 0% | 12.5 |
| October | 70% | 23% | 69 | 15 °C | 0% | 10% | 10.6 † |
| November | 34% | 28% | 66 | 10 °C | 0% | 53% | 8.8 † |
| December | 12% | 28% | 76 | 7 °C | 0% | 79% | 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 Düren → Paal, km/h | Headwind > 15 km/h, Düren → Paal | Headwind > 15 km/h, Paal → Düren | Better way |
|---|---|---|---|---|
| January | −3.5 | 16% | 4% | Paal → Düren |
| February | −2.4 | 14% | 6% | Paal → Düren |
| March | −2.0 | 13% | 6% | either |
| April | −1.2 | 9% | 5% | either |
| May | −2.0 | 10% | 3% | either |
| June | −2.6 | 8% | 2% | Paal → Düren |
| July | −4.0 | 11% | 1% | Paal → Düren |
| August | −3.5 | 9% | 1% | Paal → Düren |
| September | −2.2 | 9% | 3% | Paal → Düren |
| October | −2.0 | 11% | 4% | either |
| November | −2.5 | 13% | 4% | Paal → Düren |
| December | −3.3 | 15% | 5% | Paal → Düren |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–25 | NW | −1.6 |
| 25–51 | S | −3.3 |
| 51–76 | W | −5.0 |
| 76–101 | N | +2.6 |
| 101–126 | NW | −1.6 |
| 126–151 | SW | −4.1 |
| 151–176 | SE | +1.4 |
| 176–201 | W | −3.9 |
| 201–227 | W | −3.1 |
| 227–252 | NW | −0.5 |
| 252–277 | W | −4.1 |
| 277–302 | NW | −1.3 |
| 302–323 | W | −4.2 |
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.