BiH Trebinje: which way and when to ride
The best month for BiH Trebinje is October: 73% 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).
Also passes through Serbia
Weather by month
| Month | Good days | Rain days ≥ 1 mm | Rain, mm | Avg high | Days ≥ 30 °C | Days < 10 °C | Daylight, h |
|---|---|---|---|---|---|---|---|
| January | 11% | 25% | 97 | 4 °C | 0% | 88% | 9.3 † |
| February | 25% | 28% | 92 | 7 °C | 0% | 72% | 10.4 † |
| March | 43% | 31% | 107 | 10 °C | 0% | 47% | 11.8 |
| April | 59% | 34% | 91 | 15 °C | 0% | 17% | 13.4 |
| May | 57% | 42% | 113 | 19 °C | 1% | 3% | 14.7 |
| June | 52% | 39% | 93 | 24 °C | 11% | 0% | 15.4 |
| July | 50% | 29% | 72 | 26 °C | 24% | 0% | 15.1 |
| August | 53% | 24% | 57 | 27 °C | 25% | 0% | 14.0 |
| September | 69% | 26% | 85 | 22 °C | 5% | 1% | 12.4 |
| October | 73% | 20% | 86 | 16 °C | 0% | 12% | 10.9 † |
| November | 47% | 24% | 116 | 11 °C | 0% | 42% | 9.6 † |
| December | 12% | 23% | 101 | 5 °C | 0% | 85% | 8.9 † |
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 → Bijeljina, km/h | Headwind > 15 km/h, Trebinje → Bijeljina | Headwind > 15 km/h, Bijeljina → Trebinje | Better way |
|---|---|---|---|---|
| January | −0.1 | 2% | 1% | either |
| February | −0.4 | 4% | 2% | either |
| March | −0.6 | 4% | 4% | either |
| April | −0.6 | 3% | 3% | either |
| May | −0.4 | 2% | 2% | either |
| June | −1.2 | 1% | 1% | either |
| July | −2.0 | 1% | 1% | either |
| August | −1.6 | 1% | 0% | either |
| September | −1.1 | 1% | 1% | either |
| October | −0.4 | 2% | 1% | either |
| November | +1.0 | 1% | 2% | either |
| December | 0.0 | 2% | 2% | either |
Stages
The route is split into 4 stages of about 100–150 km between towns; each stage has its own page.
| Stage | km | Best month | Tailwind Trebinje → Bijeljina in October, km/h |
|---|---|---|---|
| 1. Trebinje → Foča | 142 | September | −0.2 |
| 2. Foča → Sokolac | 102 | October | −0.1 |
| 3. Sokolac → Zvornik | 102 | October | −0.9 |
| 4. Zvornik → Bijeljina | 69 | October | −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.