ViaRhôna, stage 1: Saint-Gingolph → Valleiry
On stage 1 (Saint-Gingolph → Valleiry, 106 km) the best month is September: 73% of days were dry with highs of 10–30 °C; the wind barely favours either direction (0.1 km/h on average; ERA5 2006–2025, 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 | 6% | 29% | 125 | 5 °C | 0% | 93% | 9.0 † |
| February | 19% | 27% | 93 | 6 °C | 0% | 78% | 10.3 † |
| March | 40% | 30% | 114 | 10 °C | 0% | 53% | 11.8 |
| April | 59% | 31% | 100 | 14 °C | 0% | 21% | 13.5 |
| May | 58% | 41% | 154 | 17 °C | 0% | 6% | 15.0 |
| June | 60% | 37% | 123 | 22 °C | 3% | 0% | 15.8 |
| July | 62% | 33% | 131 | 24 °C | 6% | 0% | 15.4 |
| August | 65% | 29% | 123 | 23 °C | 6% | 0% | 14.2 |
| September | 73% | 26% | 114 | 19 °C | 0% | 1% | 12.5 |
| October | 70% | 23% | 106 | 15 °C | 0% | 12% | 10.8 † |
| November | 32% | 30% | 131 | 9 °C | 0% | 60% | 9.3 † |
| December | 6% | 32% | 148 | 5 °C | 0% | 92% | 8.6 † |
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 Saint-Gingolph → Valleiry, km/h | Headwind > 15 km/h, Saint-Gingolph → Valleiry | Headwind > 15 km/h, Valleiry → Saint-Gingolph | Better way |
|---|---|---|---|---|
| January | +0.1 | 1% | 1% | either |
| February | −0.1 | 1% | 1% | either |
| March | −0.3 | 1% | 2% | either |
| April | −0.1 | 1% | 2% | either |
| May | −0.7 | 1% | 2% | either |
| June | −0.8 | 0% | 1% | either |
| July | −1.4 | 0% | 1% | either |
| August | −1.3 | 0% | 0% | either |
| September | −0.1 | 1% | 1% | either |
| October | 0.0 | 0% | 1% | either |
| November | −0.1 | 0% | 1% | either |
| December | −0.1 | 0% | 0% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–25 | W | −0.9 |
| 25–51 | W | −0.7 |
| 51–76 | SW | +0.7 |
| 76–101 | SW | +0.2 |
| 101–106 | SW | +0.4 |
Other stages
- Saint-Gingolph → Valleiry 106 km
- Valleiry → Montalieu 132 km
- Montalieu → Vienne 122 km
- Vienne → Le Pouzin 128 km
- Le Pouzin → Avignon 123 km
- Avignon → Sète 154 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.