39 Karlovy Vary - Zdice: which way and when to ride
The best month for 39 Karlovy Vary - Zdice is September: 77% of days were dry with highs of 10–30 °C. In September, riding Karlovy Vary → Zdice meant an average tailwind of 2.1 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 | 2% | 18% | 42 | 2 °C | 0% | 98% | 8.5 † |
| February | 7% | 16% | 32 | 3 °C | 0% | 92% | 10.0 † |
| March | 30% | 20% | 38 | 8 °C | 0% | 66% | 11.7 |
| April | 59% | 24% | 43 | 13 °C | 0% | 28% | 13.7 |
| May | 65% | 32% | 74 | 17 °C | 0% | 5% | 15.4 |
| June | 68% | 29% | 75 | 22 °C | 4% | 0% | 16.4 |
| July | 63% | 30% | 78 | 24 °C | 9% | 0% | 16.0 |
| August | 65% | 28% | 82 | 23 °C | 9% | 0% | 14.5 |
| September | 77% | 22% | 57 | 18 °C | 0% | 2% | 12.5 |
| October | 60% | 18% | 46 | 13 °C | 0% | 28% | 10.6 † |
| November | 17% | 17% | 41 | 6 °C | 0% | 81% | 8.9 † |
| December | 2% | 16% | 42 | 3 °C | 0% | 97% | 8.1 † |
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 Karlovy Vary → Zdice, km/h | Headwind > 15 km/h, Karlovy Vary → Zdice | Headwind > 15 km/h, Zdice → Karlovy Vary | Better way |
|---|---|---|---|---|
| January | +4.8 | 1% | 17% | Karlovy Vary → Zdice |
| February | +3.8 | 2% | 15% | Karlovy Vary → Zdice |
| March | +3.3 | 4% | 15% | Karlovy Vary → Zdice |
| April | +1.9 | 3% | 11% | either |
| May | +1.6 | 5% | 10% | either |
| June | +3.0 | 1% | 9% | Karlovy Vary → Zdice |
| July | +4.9 | 0% | 12% | Karlovy Vary → Zdice |
| August | +3.0 | 0% | 7% | Karlovy Vary → Zdice |
| September | +2.1 | 2% | 8% | Karlovy Vary → Zdice |
| October | +2.6 | 1% | 10% | Karlovy Vary → Zdice |
| November | +3.0 | 1% | 12% | Karlovy Vary → Zdice |
| December | +4.4 | 1% | 14% | Karlovy Vary → Zdice |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–25 | SE | +2.2 |
| 25–50 | E | +2.3 |
| 50–76 | E | +2.4 |
| 76–101 | E | +2.4 |
| 101–127 | SE | +1.3 |
| 127–147 | SE | +2.0 |
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.