Rannikkoreitti: which way and when to ride
The best month for Rannikkoreitti is June: 80% of days were dry with highs of 10–30 °C. In June the wind barely favours either direction — on average 0.1 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 | 0% | 22% | 56 | -1 °C | 0% | 100% | 6.7 † |
| February | 0% | 19% | 42 | -1 °C | 0% | 100% | 9.0 † |
| March | 1% | 15% | 35 | 2 °C | 0% | 99% | 11.6 |
| April | 19% | 15% | 35 | 7 °C | 0% | 80% | 14.5 |
| May | 62% | 15% | 36 | 13 °C | 0% | 29% | 17.1 |
| June | 80% | 20% | 53 | 18 °C | 0% | 1% | 18.8 |
| July | 76% | 24% | 66 | 21 °C | 1% | 0% | 18.1 |
| August | 72% | 28% | 82 | 20 °C | 0% | 0% | 15.6 |
| September | 74% | 23% | 62 | 15 °C | 0% | 4% | 12.7 |
| October | 34% | 24% | 72 | 9 °C | 0% | 51% | 10.0 † |
| November | 3% | 24% | 65 | 5 °C | 0% | 95% | 7.4 † |
| December | 0% | 25% | 65 | 2 °C | 0% | 100% | 5.9 † |
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 Salo → Raseborg, km/h | Headwind > 15 km/h, Salo → Raseborg | Headwind > 15 km/h, Raseborg → Salo | Better way |
|---|---|---|---|---|
| January | −0.6 | 18% | 15% | either |
| February | −0.9 | 14% | 12% | either |
| March | +0.2 | 14% | 15% | either |
| April | +0.5 | 12% | 14% | either |
| May | −0.4 | 12% | 12% | either |
| June | +0.1 | 13% | 14% | either |
| July | −0.1 | 12% | 13% | either |
| August | −0.9 | 15% | 12% | either |
| September | −0.2 | 15% | 14% | either |
| October | −0.1 | 17% | 16% | either |
| November | −0.7 | 17% | 15% | either |
| December | −0.6 | 19% | 16% | either |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in June, km/h |
|---|---|---|
| 0–25 | SW | −5.0 |
| 25–50 | SW | −5.2 |
| 50–76 | SW | −9.3 |
| 76–101 | SW | −6.2 |
| 101–126 | E | +4.3 |
| 126–152 | E | +6.9 |
| 152–177 | NE | +7.7 |
| 177–185 | NE | +6.3 |
| 185–211 | SE | −0.7 |
| 211–237 | E | +4.5 |
| 237–252 | SE | +3.0 |
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.