BiH Trebinje, stage 1: Trebinje → Foča
On stage 1 (Trebinje → Foča, 142 km) the best month is September: 71% of days were dry with highs of 10–30 °C; the wind barely favours either direction (0.1 km/h on average; ERA5 2006–2025, 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 | 5% | 29% | 146 | 4 °C | 0% | 94% | 9.3 † |
| February | 18% | 31% | 137 | 6 °C | 0% | 80% | 10.5 † |
| March | 37% | 35% | 148 | 9 °C | 0% | 54% | 11.8 |
| April | 55% | 38% | 109 | 14 °C | 0% | 20% | 13.3 |
| May | 55% | 45% | 119 | 18 °C | 0% | 3% | 14.7 |
| June | 59% | 37% | 80 | 23 °C | 5% | 0% | 15.3 |
| July | 56% | 26% | 59 | 26 °C | 20% | 0% | 15.1 |
| August | 59% | 23% | 50 | 26 °C | 18% | 0% | 13.9 |
| September | 71% | 27% | 110 | 21 °C | 1% | 1% | 12.4 |
| October | 71% | 23% | 125 | 16 °C | 0% | 10% | 10.9 † |
| November | 43% | 30% | 190 | 10 °C | 0% | 43% | 9.6 † |
| December | 7% | 27% | 149 | 5 °C | 0% | 89% | 9.0 † |
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 Trebinje → Foča, km/h | Headwind > 15 km/h, Trebinje → Foča | Headwind > 15 km/h, Foča → Trebinje | Better way |
|---|---|---|---|---|
| January | −1.2 | 5% | 2% | either |
| February | −0.8 | 8% | 3% | either |
| March | −0.3 | 8% | 4% | either |
| April | +0.6 | 5% | 3% | either |
| May | +1.2 | 3% | 3% | either |
| June | +0.1 | 3% | 2% | either |
| July | −0.9 | 3% | 1% | either |
| August | −0.3 | 2% | 1% | either |
| September | −0.1 | 3% | 1% | either |
| October | −0.2 | 4% | 2% | either |
| November | +1.0 | 2% | 3% | either |
| December | −1.3 | 5% | 3% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–26 | N | +1.3 |
| 26–51 | N | +0.1 |
| 51–76 | NE | 0.0 |
| 76–103 | N | −0.7 |
| 103–128 | NE | −0.7 |
| 128–142 | N | −0.8 |
Other stages
- Trebinje → Foča 142 km
- Foča → Sokolac 102 km
- Sokolac → Zvornik 102 km
- Zvornik → Bijeljina 69 km
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.