EuroVelo 9 - Baltic-Adriatic - part Slovenia: which way and when to ride
The best month for EuroVelo 9 - Baltic-Adriatic - part Slovenia is October: 76% of days were dry with highs of 10–30 °C. In October the wind barely favours either direction — on average 1.7 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 | 12% | 14% | 51 | 4 °C | 0% | 86% | 9.0 † |
| February | 28% | 17% | 59 | 7 °C | 0% | 68% | 10.3 † |
| March | 55% | 19% | 60 | 12 °C | 0% | 35% | 11.8 |
| April | 70% | 24% | 67 | 17 °C | 0% | 11% | 13.5 |
| May | 63% | 36% | 117 | 20 °C | 0% | 1% | 15.0 |
| June | 57% | 32% | 99 | 25 °C | 13% | 0% | 15.8 |
| July | 52% | 29% | 98 | 27 °C | 23% | 0% | 15.4 |
| August | 59% | 24% | 100 | 26 °C | 19% | 0% | 14.2 |
| September | 74% | 25% | 111 | 21 °C | 1% | 0% | 12.5 |
| October | 76% | 18% | 74 | 16 °C | 0% | 9% | 10.8 † |
| November | 39% | 19% | 77 | 9 °C | 0% | 54% | 9.3 † |
| December | 10% | 15% | 56 | 5 °C | 0% | 89% | 8.6 † |
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 Šentilj → Celje, km/h | Headwind > 15 km/h, Šentilj → Celje | Headwind > 15 km/h, Celje → Šentilj | Better way |
|---|---|---|---|---|
| January | −1.4 | 3% | 2% | either |
| February | −0.7 | 4% | 4% | either |
| March | −0.3 | 6% | 6% | either |
| April | −0.5 | 5% | 4% | either |
| May | −0.2 | 3% | 4% | either |
| June | −0.4 | 3% | 2% | either |
| July | −0.2 | 1% | 2% | either |
| August | 0.0 | 1% | 1% | either |
| September | +0.3 | 2% | 2% | either |
| October | −1.7 | 4% | 2% | either |
| November | −1.6 | 3% | 2% | either |
| December | −1.2 | 2% | 2% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in October, km/h |
|---|---|---|
| 0–25 | S | −1.9 |
| 25–50 | S | −2.0 |
| 50–75 | S | −1.8 |
| 75–101 | SW | −1.8 |
| 101–119 | W | −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.