Slovenian Way of St. James: which way and when to ride
The best month for Slovenian Way of St. James is October: 73% of days were dry with highs of 10–30 °C. In October the wind barely favours either direction — on average 1.0 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 | 10% | 19% | 82 | 5 °C | 0% | 88% | 9.0 † |
| February | 25% | 22% | 91 | 7 °C | 0% | 72% | 10.3 † |
| March | 52% | 25% | 92 | 11 °C | 0% | 37% | 11.8 |
| April | 66% | 29% | 89 | 16 °C | 0% | 10% | 13.5 |
| May | 59% | 40% | 136 | 20 °C | 0% | 1% | 14.9 |
| June | 57% | 33% | 108 | 25 °C | 10% | 0% | 15.7 |
| July | 51% | 30% | 107 | 27 °C | 22% | 0% | 15.4 |
| August | 56% | 27% | 116 | 26 °C | 19% | 0% | 14.1 |
| September | 71% | 28% | 146 | 21 °C | 1% | 0% | 12.5 |
| October | 73% | 23% | 114 | 16 °C | 0% | 8% | 10.8 † |
| November | 39% | 25% | 128 | 10 °C | 0% | 48% | 9.4 † |
| December | 10% | 19% | 93 | 6 °C | 0% | 87% | 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 near Brežice → Trieste, km/h | Headwind > 15 km/h, near Brežice → Trieste | Headwind > 15 km/h, Trieste → near Brežice | Better way |
|---|---|---|---|---|
| January | +0.7 | 2% | 4% | either |
| February | +1.3 | 3% | 6% | either |
| March | +1.1 | 4% | 7% | either |
| April | +0.5 | 3% | 4% | either |
| May | +0.3 | 2% | 3% | either |
| June | +0.1 | 2% | 2% | either |
| July | +1.0 | 1% | 2% | either |
| August | +2.4 | 1% | 2% | near Brežice → Trieste |
| September | +2.5 | 1% | 4% | near Brežice → Trieste |
| October | +1.0 | 2% | 4% | either |
| November | +0.9 | 2% | 4% | either |
| December | +0.8 | 1% | 3% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in October, km/h |
|---|---|---|
| 0–4 | E | −0.6 |
| 4–29 | W | +0.2 |
| 29–54 | W | +0.5 |
| 54–79 | W | +0.4 |
| 79–104 | NW | +1.1 |
| 104–130 | NW | +1.2 |
| 130–155 | NW | +0.5 |
| 155–180 | NW | +0.6 |
| 180–205 | W | +0.5 |
| 205–230 | SW | +0.9 |
| 230–255 | SW | +0.9 |
| 255–280 | W | +2.8 |
| 280–306 | SW | +2.6 |
| 306–322 | S | +1.8 |
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.