Ruta dels Llacs: which way and when to ride
The best month for Ruta dels Llacs is October: 84% of days were dry with highs of 10–30 °C. In October, riding Lleida → near Tremp meant an average tailwind of 3.3 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 | 50% | 10% | 32 | 10 °C | 0% | 47% | 9.4 † |
| February | 69% | 11% | 29 | 12 °C | 0% | 27% | 10.5 † |
| March | 76% | 17% | 56 | 16 °C | 0% | 13% | 11.8 |
| April | 76% | 23% | 71 | 19 °C | 1% | 4% | 13.3 |
| May | 71% | 19% | 58 | 23 °C | 10% | 0% | 14.5 |
| June | 46% | 19% | 50 | 28 °C | 38% | 0% | 15.2 |
| July | 30% | 13% | 43 | 31 °C | 61% | 0% | 14.9 |
| August | 33% | 16% | 45 | 31 °C | 56% | 0% | 13.8 |
| September | 66% | 17% | 58 | 26 °C | 19% | 0% | 12.4 |
| October | 84% | 14% | 71 | 21 °C | 1% | 1% | 11.0 † |
| November | 77% | 13% | 53 | 14 °C | 0% | 14% | 9.7 † |
| December | 56% | 9% | 26 | 11 °C | 0% | 41% | 9.1 † |
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 Lleida → near Tremp, km/h | Headwind > 15 km/h, Lleida → near Tremp | Headwind > 15 km/h, near Tremp → Lleida | Better way |
|---|---|---|---|---|
| January | +1.3 | 0% | 0% | either |
| February | +1.9 | 1% | 0% | either |
| March | +2.8 | 2% | 1% | Lleida → near Tremp |
| April | +4.0 | 1% | 1% | Lleida → near Tremp |
| May | +4.7 | 1% | 1% | Lleida → near Tremp |
| June | +5.9 | 0% | 2% | Lleida → near Tremp |
| July | +6.9 | 0% | 2% | Lleida → near Tremp |
| August | +6.4 | 0% | 1% | Lleida → near Tremp |
| September | +4.8 | 0% | 0% | Lleida → near Tremp |
| October | +3.3 | 0% | 0% | Lleida → near Tremp |
| November | +1.5 | 0% | 0% | either |
| December | +1.0 | 0% | 0% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in October, km/h |
|---|---|---|
| 0–25 | NE | +4.0 |
| 25–50 | N | +3.4 |
| 50–75 | N | +3.4 |
| 75–101 | N | +2.4 |
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.