Via Fluvia: which way and when to ride
The best month for Via Fluvia is September: 77% of days were dry with highs of 10–30 °C. In September the wind barely favours either direction — on average 0.2 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 | 12% | 23% | 62 | 5 °C | 0% | 87% | 9.1 † |
| February | 27% | 21% | 54 | 7 °C | 0% | 71% | 10.3 † |
| March | 46% | 26% | 73 | 11 °C | 0% | 45% | 11.8 |
| April | 59% | 33% | 82 | 14 °C | 0% | 19% | 13.4 |
| May | 61% | 38% | 108 | 17 °C | 0% | 5% | 14.8 |
| June | 62% | 33% | 88 | 22 °C | 5% | 0% | 15.6 |
| July | 64% | 27% | 81 | 25 °C | 11% | 0% | 15.3 |
| August | 66% | 22% | 69 | 25 °C | 14% | 0% | 14.1 |
| September | 77% | 21% | 77 | 20 °C | 1% | 1% | 12.5 |
| October | 70% | 23% | 96 | 16 °C | 0% | 11% | 10.9 † |
| November | 36% | 27% | 100 | 10 °C | 0% | 52% | 9.4 † |
| December | 17% | 25% | 69 | 6 °C | 0% | 79% | 8.8 † |
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 Riotord → Landos, km/h | Headwind > 15 km/h, Riotord → Landos | Headwind > 15 km/h, Landos → Riotord | Better way |
|---|---|---|---|---|
| January | −1.7 | 5% | 2% | either |
| February | −1.5 | 6% | 3% | either |
| March | −1.0 | 8% | 4% | either |
| April | −0.1 | 5% | 4% | either |
| May | −0.4 | 5% | 4% | either |
| June | −0.3 | 3% | 3% | either |
| July | −0.5 | 3% | 2% | either |
| August | −0.3 | 2% | 2% | either |
| September | −0.2 | 4% | 2% | either |
| October | −0.9 | 6% | 3% | either |
| November | −1.7 | 5% | 2% | either |
| December | −2.3 | 5% | 2% | Landos → Riotord |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–7 | NE | −0.8 |
| 7–32 | NW | −1.7 |
| 32–57 | W | −0.3 |
| 57–82 | SW | +0.2 |
| 82–107 | W | −0.5 |
| 107–121 | W | −1.6 |
| 121–146 | S | +1.6 |
| 146–156 | S | +1.7 |
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.