Aare Route: which way and when to ride
The best month for Aare Route is September: 64% of days were dry with highs of 10–30 °C. In September the wind barely favours either direction — on average 0.8 km/h along the route (ERA5 2006–2025, daytime 9:00–18:00).
Weather by month
| Month | Good days | Rain days ≥ 1 mm | Rain, mm | Avg high | Days ≥ 30 °C | Days < 10 °C | Daylight, h |
|---|---|---|---|---|---|---|---|
| January | 4% | 27% | 105 | 2 °C | 0% | 95% | 8.9 † |
| February | 13% | 27% | 79 | 4 °C | 0% | 85% | 10.2 † |
| March | 29% | 32% | 101 | 7 °C | 0% | 64% | 11.8 |
| April | 46% | 34% | 105 | 12 °C | 0% | 39% | 13.5 |
| May | 45% | 48% | 161 | 15 °C | 0% | 21% | 15.0 |
| June | 49% | 47% | 159 | 20 °C | 3% | 5% | 15.9 |
| July | 50% | 45% | 172 | 22 °C | 6% | 2% | 15.5 |
| August | 53% | 42% | 170 | 21 °C | 5% | 3% | 14.2 |
| September | 64% | 32% | 120 | 17 °C | 0% | 9% | 12.5 |
| October | 56% | 26% | 106 | 12 °C | 0% | 30% | 10.8 † |
| November | 19% | 29% | 109 | 6 °C | 0% | 76% | 9.3 † |
| December | 3% | 31% | 120 | 2 °C | 0% | 95% | 8.5 † |
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 near Meiringen → Koblenz, km/h | Headwind > 15 km/h, near Meiringen → Koblenz | Headwind > 15 km/h, Koblenz → near Meiringen | Better way |
|---|---|---|---|---|
| January | +1.0 | 1% | 4% | either |
| February | +0.4 | 2% | 3% | either |
| March | −0.2 | 2% | 4% | either |
| April | −0.9 | 1% | 1% | either |
| May | −0.8 | 1% | 2% | either |
| June | −1.1 | 1% | 1% | either |
| July | −0.8 | 0% | 1% | either |
| August | −0.6 | 0% | 1% | either |
| September | −0.8 | 1% | 1% | either |
| October | −0.1 | 1% | 1% | either |
| November | +0.9 | 0% | 2% | either |
| December | +1.5 | 1% | 3% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–25 | NW | −0.5 |
| 25–50 | NW | −1.5 |
| 50–75 | SW | +0.2 |
| 75–101 | NW | −2.9 |
| 101–126 | NW | −3.2 |
| 126–151 | W | −0.8 |
| 151–176 | N | −0.9 |
| 176–201 | NE | −0.3 |
| 201–226 | E | +0.1 |
| 226–251 | NE | −0.4 |
| 251–277 | NE | +0.4 |
| 277–302 | NE | −0.1 |
| 302–310 | N | −0.3 |
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.