Sava: which way and when to ride
The best month for Sava is October: 81% of days were dry with highs of 10–30 °C. In October the wind barely favours either direction — on average 0.4 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 | 20% | 16% | 61 | 6 °C | 0% | 77% | 9.1 † |
| February | 38% | 19% | 60 | 9 °C | 0% | 56% | 10.3 † |
| March | 63% | 20% | 63 | 14 °C | 0% | 25% | 11.8 |
| April | 75% | 22% | 61 | 19 °C | 0% | 6% | 13.5 |
| May | 66% | 31% | 97 | 22 °C | 5% | 0% | 14.9 |
| June | 47% | 25% | 75 | 27 °C | 30% | 0% | 15.7 |
| July | 36% | 20% | 71 | 30 °C | 48% | 0% | 15.3 |
| August | 42% | 16% | 68 | 29 °C | 45% | 0% | 14.1 |
| September | 70% | 20% | 93 | 24 °C | 10% | 0% | 12.5 |
| October | 81% | 17% | 79 | 18 °C | 0% | 4% | 10.8 † |
| November | 49% | 18% | 78 | 11 °C | 0% | 41% | 9.4 † |
| December | 18% | 16% | 65 | 6 °C | 0% | 78% | 8.7 † |
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 Zagreb → Jasenovac, km/h | Headwind > 15 km/h, Zagreb → Jasenovac | Headwind > 15 km/h, Jasenovac → Zagreb | Better way |
|---|---|---|---|---|
| January | −0.2 | 0% | 0% | either |
| February | +0.3 | 0% | 1% | either |
| March | +0.5 | 0% | 1% | either |
| April | +0.7 | 0% | 1% | either |
| May | +0.9 | 0% | 1% | either |
| June | +0.6 | 0% | 1% | either |
| July | 0.0 | 0% | 1% | either |
| August | −0.9 | 0% | 0% | either |
| September | −0.2 | 0% | 0% | either |
| October | −0.4 | 0% | 1% | either |
| November | −0.8 | 0% | 0% | either |
| December | −0.4 | 0% | 0% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in October, km/h |
|---|---|---|
| 0–26 | SE | −0.4 |
| 26–51 | SE | −0.3 |
| 51–76 | S | +0.3 |
| 76–102 | SE | −0.5 |
| 102–127 | SE | −0.6 |
| 127–150 | SE | −0.8 |
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.