La Littorale : Roscoff - Saint-Pabu: which way and when to ride
The best month for La Littorale : Roscoff - Saint-Pabu is August: 79% of days were dry with highs of 10–30 °C. In August, riding Saint-Pabu → Roscoff meant an average tailwind of 6.8 km/h (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 | 29% | 32% | 95 | 10 °C | 0% | 51% | 8.7 † |
| February | 38% | 30% | 83 | 10 °C | 0% | 43% | 10.1 † |
| March | 49% | 31% | 72 | 11 °C | 0% | 29% | 11.7 |
| April | 70% | 24% | 58 | 14 °C | 0% | 7% | 13.6 |
| May | 76% | 24% | 62 | 16 °C | 0% | 0% | 15.2 |
| June | 73% | 26% | 59 | 18 °C | 0% | 0% | 16.1 |
| July | 73% | 26% | 50 | 20 °C | 1% | 0% | 15.8 |
| August | 79% | 21% | 55 | 20 °C | 1% | 0% | 14.3 |
| September | 77% | 23% | 54 | 19 °C | 0% | 0% | 12.5 |
| October | 73% | 26% | 91 | 16 °C | 0% | 1% | 10.7 † |
| November | 57% | 34% | 104 | 13 °C | 0% | 14% | 9.1 † |
| December | 39% | 33% | 106 | 10 °C | 0% | 37% | 8.3 † |
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 Roscoff → Saint-Pabu, km/h | Headwind > 15 km/h, Roscoff → Saint-Pabu | Headwind > 15 km/h, Saint-Pabu → Roscoff | Better way |
|---|---|---|---|---|
| January | −7.2 | 35% | 10% | Saint-Pabu → Roscoff |
| February | −6.1 | 33% | 13% | Saint-Pabu → Roscoff |
| March | −2.9 | 28% | 19% | Saint-Pabu → Roscoff |
| April | 0.0 | 19% | 18% | either |
| May | −2.2 | 22% | 15% | Saint-Pabu → Roscoff |
| June | −2.8 | 22% | 13% | Saint-Pabu → Roscoff |
| July | −7.0 | 30% | 6% | Saint-Pabu → Roscoff |
| August | −6.8 | 28% | 6% | Saint-Pabu → Roscoff |
| September | −3.4 | 24% | 11% | Saint-Pabu → Roscoff |
| October | −5.3 | 28% | 9% | Saint-Pabu → Roscoff |
| November | −6.8 | 32% | 9% | Saint-Pabu → Roscoff |
| December | −8.7 | 39% | 10% | Saint-Pabu → Roscoff |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in August, km/h |
|---|---|---|
| 0–25 | W | −6.6 |
| 25–50 | W | −7.4 |
| 50–76 | W | −7.4 |
| 76–101 | SW | −6.3 |
| 101–126 | SW | −6.3 |
| 126–139 | NW | −7.2 |
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.