22 České Petrovice - Chrastava: which way and when to ride
The best month for 22 České Petrovice - Chrastava is September: 72% of days were dry with highs of 10–30 °C. In September the wind barely favours either direction — on average 1.1 km/h along the route (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 | 0% | 27% | 71 | 0 °C | 0% | 99% | 8.4 † |
| February | 2% | 21% | 54 | 2 °C | 0% | 98% | 10.0 † |
| March | 23% | 25% | 56 | 6 °C | 0% | 74% | 11.7 |
| April | 53% | 27% | 50 | 12 °C | 0% | 35% | 13.7 |
| May | 62% | 34% | 85 | 16 °C | 0% | 9% | 15.5 |
| June | 65% | 34% | 90 | 21 °C | 1% | 0% | 16.4 |
| July | 60% | 37% | 100 | 22 °C | 3% | 0% | 16.0 |
| August | 66% | 31% | 104 | 22 °C | 3% | 0% | 14.5 |
| September | 72% | 26% | 78 | 17 °C | 0% | 4% | 12.5 |
| October | 51% | 24% | 63 | 12 °C | 0% | 39% | 10.6 † |
| November | 14% | 22% | 58 | 6 °C | 0% | 83% | 8.9 † |
| December | 1% | 22% | 59 | 2 °C | 0% | 99% | 8.0 † |
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 near Międzylesie → Chrastava, km/h | Headwind > 15 km/h, near Międzylesie → Chrastava | Headwind > 15 km/h, Chrastava → near Międzylesie | Better way |
|---|---|---|---|---|
| January | −1.3 | 9% | 2% | either |
| February | −1.5 | 9% | 4% | either |
| March | −1.9 | 9% | 4% | either |
| April | −1.6 | 9% | 4% | either |
| May | −1.2 | 7% | 4% | either |
| June | −2.4 | 7% | 2% | Chrastava → near Międzylesie |
| July | −3.6 | 7% | 1% | Chrastava → near Międzylesie |
| August | −1.7 | 4% | 1% | either |
| September | −1.1 | 5% | 3% | either |
| October | −0.2 | 6% | 4% | either |
| November | +0.6 | 5% | 5% | either |
| December | −0.3 | 7% | 3% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–25 | NW | −0.2 |
| 25–50 | NW | −1.0 |
| 50–76 | NW | −0.3 |
| 76–101 | N | +0.6 |
| 101–119 | W | −2.3 |
| 119–132 | W | −2.5 |
| 132–157 | NW | −0.9 |
| 157–182 | NW | −1.5 |
| 182–207 | NW | −1.8 |
| 207–229 | W | −2.1 |
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.