La Vélidéale, stage 6: Nantes → Saint-Nazaire
On stage 6 (Nantes → Saint-Nazaire, 88 km) the best month is September: 81% of days were dry with highs of 10–30 °C, and riding Saint-Nazaire → Nantes meant an average tailwind of 3.1 km/h (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 | 32% | 22% | 72 | 9 °C | 0% | 53% | 8.9 † |
| February | 46% | 20% | 57 | 10 °C | 0% | 39% | 10.2 † |
| March | 63% | 24% | 60 | 13 °C | 0% | 18% | 11.8 |
| April | 78% | 20% | 50 | 16 °C | 0% | 2% | 13.6 |
| May | 78% | 22% | 56 | 19 °C | 0% | 0% | 15.1 |
| June | 78% | 18% | 51 | 22 °C | 4% | 0% | 15.9 |
| July | 76% | 16% | 44 | 24 °C | 8% | 0% | 15.6 |
| August | 77% | 15% | 43 | 23 °C | 7% | 0% | 14.2 |
| September | 81% | 17% | 44 | 21 °C | 2% | 0% | 12.5 |
| October | 78% | 22% | 75 | 17 °C | 0% | 1% | 10.8 † |
| November | 62% | 24% | 78 | 13 °C | 0% | 15% | 9.2 † |
| December | 38% | 25% | 79 | 10 °C | 0% | 42% | 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 Nantes → Saint-Nazaire, km/h | Headwind > 15 km/h, Nantes → Saint-Nazaire | Headwind > 15 km/h, Saint-Nazaire → Nantes | Better way |
|---|---|---|---|---|
| January | −3.7 | 20% | 5% | Saint-Nazaire → Nantes |
| February | −3.4 | 20% | 7% | Saint-Nazaire → Nantes |
| March | −2.6 | 19% | 8% | Saint-Nazaire → Nantes |
| April | −1.6 | 13% | 8% | either |
| May | −3.9 | 19% | 6% | Saint-Nazaire → Nantes |
| June | −4.4 | 16% | 4% | Saint-Nazaire → Nantes |
| July | −7.2 | 23% | 3% | Saint-Nazaire → Nantes |
| August | −6.6 | 19% | 2% | Saint-Nazaire → Nantes |
| September | −3.1 | 14% | 5% | Saint-Nazaire → Nantes |
| October | −1.6 | 13% | 6% | either |
| November | −3.4 | 18% | 6% | Saint-Nazaire → Nantes |
| December | −3.3 | 20% | 6% | Saint-Nazaire → Nantes |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 595–620 | W | −3.2 |
| 620–645 | NW | −2.9 |
| 645–670 | W | −3.5 |
| 670–682 | SW | −2.5 |
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.