Tierras de Frontera: which way and when to ride
The best month for Tierras de Frontera is October: 82% of days were dry with highs of 10–30 °C. In October, riding Atienza → Calatayud meant an average tailwind of 2.3 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 | 31% | 16% | 39 | 8 °C | 0% | 68% | 9.5 † |
| February | 51% | 18% | 38 | 10 °C | 0% | 45% | 10.6 † |
| March | 60% | 25% | 58 | 13 °C | 0% | 29% | 11.8 |
| April | 67% | 31% | 65 | 16 °C | 0% | 8% | 13.3 |
| May | 72% | 25% | 54 | 21 °C | 3% | 1% | 14.5 |
| June | 55% | 23% | 42 | 26 °C | 26% | 0% | 15.1 |
| July | 29% | 10% | 16 | 31 °C | 66% | 0% | 14.8 |
| August | 35% | 10% | 15 | 30 °C | 59% | 0% | 13.8 |
| September | 77% | 13% | 31 | 25 °C | 10% | 0% | 12.4 |
| October | 82% | 16% | 51 | 20 °C | 0% | 3% | 11.0 |
| November | 61% | 17% | 50 | 12 °C | 0% | 30% | 9.8 † |
| December | 36% | 12% | 33 | 9 °C | 0% | 61% | 9.2 † |
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 Atienza → Calatayud, km/h | Headwind > 15 km/h, Atienza → Calatayud | Headwind > 15 km/h, Calatayud → Atienza | Better way |
|---|---|---|---|---|
| January | +3.5 | 4% | 14% | Atienza → Calatayud |
| February | +2.9 | 4% | 15% | Atienza → Calatayud |
| March | +2.2 | 7% | 16% | Atienza → Calatayud |
| April | +1.8 | 5% | 12% | either |
| May | +1.9 | 4% | 11% | either |
| June | +2.3 | 3% | 10% | Atienza → Calatayud |
| July | +2.3 | 2% | 10% | Atienza → Calatayud |
| August | +1.8 | 3% | 8% | either |
| September | +1.2 | 3% | 6% | either |
| October | +2.3 | 4% | 10% | Atienza → Calatayud |
| November | +3.1 | 5% | 14% | Atienza → Calatayud |
| December | +3.3 | 3% | 12% | Atienza → Calatayud |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in October, km/h |
|---|---|---|
| 0–25 | SW | −3.7 |
| 25–50 | SE | −0.3 |
| 50–76 | NE | +4.5 |
| 76–101 | E | +3.9 |
| 101–126 | E | +4.2 |
| 126–152 | NW | −2.0 |
| 152–177 | NE | +4.1 |
| 177–202 | NE | +4.4 |
| 202–227 | E | +4.4 |
| 227–247 | E | +3.9 |
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.