La Vélidéale, stage 4: Niort → Nueil-les-Aubiers
On stage 4 (Niort → Nueil-les-Aubiers, 104 km) the best month is September: 79% of days were dry with highs of 10–30 °C; the wind barely favours either direction (0.8 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 | 24% | 23% | 74 | 8 °C | 0% | 64% | 8.9 † |
| February | 40% | 25% | 64 | 10 °C | 0% | 46% | 10.2 † |
| March | 58% | 27% | 68 | 13 °C | 0% | 23% | 11.8 |
| April | 74% | 24% | 57 | 16 °C | 0% | 3% | 13.5 |
| May | 71% | 29% | 73 | 19 °C | 1% | 0% | 15.0 |
| June | 69% | 24% | 64 | 23 °C | 7% | 0% | 15.8 |
| July | 74% | 14% | 36 | 25 °C | 13% | 0% | 15.5 |
| August | 73% | 13% | 39 | 25 °C | 15% | 0% | 14.2 |
| September | 79% | 17% | 48 | 22 °C | 5% | 0% | 12.5 |
| October | 77% | 22% | 78 | 18 °C | 0% | 1% | 10.8 † |
| November | 55% | 27% | 80 | 12 °C | 0% | 23% | 9.3 † |
| December | 29% | 23% | 78 | 9 °C | 0% | 54% | 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 Niort → Nueil-les-Aubiers, km/h | Headwind > 15 km/h, Niort → Nueil-les-Aubiers | Headwind > 15 km/h, Nueil-les-Aubiers → Niort | Better way |
|---|---|---|---|---|
| January | +1.0 | 7% | 11% | either |
| February | +0.7 | 9% | 12% | either |
| March | 0.0 | 9% | 10% | either |
| April | −0.8 | 7% | 6% | either |
| May | −1.0 | 7% | 6% | either |
| June | −0.5 | 4% | 5% | either |
| July | −0.6 | 4% | 5% | either |
| August | −0.7 | 3% | 4% | either |
| September | −0.8 | 6% | 5% | either |
| October | +1.4 | 5% | 10% | either |
| November | +1.7 | 7% | 12% | either |
| December | +2.0 | 7% | 12% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 350–375 | N | −0.3 |
| 375–401 | NE | +0.2 |
| 401–426 | NW | −1.8 |
| 426–454 | NW | −1.4 |
Other stages
- Royère-de-Vassivière → Aixe-sur-Vienne 100 km
- Aixe-sur-Vienne → Ruffec 136 km
- Ruffec → Niort 114 km
- Niort → Nueil-les-Aubiers 104 km
- Nueil-les-Aubiers → Nantes 132 km
- Nantes → Saint-Nazaire 88 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.