Green Velo - 11 Ziemia Sandomierska i Dolina Dolnego Sanu: which way and when to ride
The best month for Green Velo - 11 Ziemia Sandomierska i Dolina Dolnego Sanu is September: 78% of days were dry with highs of 10–30 °C. In September the wind barely favours either direction — on average 0.8 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 | 2% | 22% | 51 | 1 °C | 0% | 97% | 8.4 † |
| February | 6% | 18% | 40 | 3 °C | 0% | 92% | 10.0 † |
| March | 33% | 20% | 48 | 8 °C | 0% | 62% | 11.7 |
| April | 64% | 23% | 49 | 15 °C | 0% | 21% | 13.7 |
| May | 66% | 33% | 81 | 19 °C | 1% | 2% | 15.4 |
| June | 66% | 28% | 75 | 24 °C | 7% | 0% | 16.4 |
| July | 56% | 31% | 95 | 26 °C | 16% | 0% | 16.0 |
| August | 62% | 24% | 75 | 25 °C | 16% | 0% | 14.5 |
| September | 78% | 20% | 72 | 20 °C | 1% | 1% | 12.5 |
| October | 68% | 17% | 53 | 14 °C | 0% | 21% | 10.6 † |
| November | 30% | 18% | 46 | 8 °C | 0% | 65% | 8.9 † |
| December | 4% | 17% | 44 | 3 °C | 0% | 96% | 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 Głuchów → near Staszów, km/h | Headwind > 15 km/h, Głuchów → near Staszów | Headwind > 15 km/h, near Staszów → Głuchów | Better way |
|---|---|---|---|---|
| January | −1.0 | 12% | 8% | either |
| February | −0.9 | 11% | 8% | either |
| March | −1.8 | 12% | 7% | either |
| April | −1.7 | 11% | 5% | either |
| May | −1.0 | 8% | 4% | either |
| June | −2.0 | 8% | 3% | either |
| July | −3.0 | 8% | 2% | near Staszów → Głuchów |
| August | −1.0 | 5% | 2% | either |
| September | −0.8 | 8% | 5% | either |
| October | 0.0 | 8% | 7% | either |
| November | +0.6 | 8% | 8% | either |
| December | −0.7 | 11% | 8% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–25 | N | −0.2 |
| 25–51 | NE | +1.2 |
| 51–76 | NW | −0.7 |
| 76–102 | NW | −1.0 |
| 102–127 | W | −1.5 |
| 127–153 | W | −1.2 |
| 153–178 | NW | −1.6 |
| 178–201 | W | −1.3 |
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.