Hämeen härkätie: which way and when to ride
The best month for Hämeen härkätie is June: 68% of days were dry with highs of 10–30 °C. In June, riding Turku → Hämeenlinna meant an average tailwind of 3.7 km/h (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% | 19% | 48 | -3 °C | 0% | 100% | 6.5 † |
| February | 0% | 17% | 37 | -2 °C | 0% | 100% | 8.9 † |
| March | 4% | 15% | 34 | 2 °C | 0% | 96% | 11.6 |
| April | 32% | 18% | 38 | 8 °C | 0% | 67% | 14.5 |
| May | 67% | 24% | 49 | 15 °C | 0% | 16% | 17.3 |
| June | 68% | 30% | 70 | 19 °C | 1% | 1% | 19.1 |
| July | 64% | 34% | 81 | 22 °C | 2% | 0% | 18.3 |
| August | 66% | 33% | 83 | 20 °C | 0% | 0% | 15.7 |
| September | 68% | 26% | 57 | 15 °C | 0% | 8% | 12.8 |
| October | 28% | 21% | 59 | 8 °C | 0% | 62% | 9.9 † |
| November | 3% | 20% | 51 | 4 °C | 0% | 97% | 7.2 † |
| December | 0% | 21% | 54 | 0 °C | 0% | 100% | 5.7 † |
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 Turku → Hämeenlinna, km/h | Headwind > 15 km/h, Turku → Hämeenlinna | Headwind > 15 km/h, Hämeenlinna → Turku | Better way |
|---|---|---|---|---|
| January | +1.8 | 3% | 10% | either |
| February | +2.0 | 2% | 8% | Turku → Hämeenlinna |
| March | +2.9 | 3% | 10% | Turku → Hämeenlinna |
| April | +2.7 | 3% | 9% | Turku → Hämeenlinna |
| May | +2.9 | 3% | 9% | Turku → Hämeenlinna |
| June | +3.7 | 2% | 9% | Turku → Hämeenlinna |
| July | +2.8 | 2% | 8% | Turku → Hämeenlinna |
| August | +3.3 | 2% | 9% | Turku → Hämeenlinna |
| September | +3.2 | 2% | 10% | Turku → Hämeenlinna |
| October | +3.2 | 3% | 11% | Turku → Hämeenlinna |
| November | +2.4 | 4% | 9% | Turku → Hämeenlinna |
| December | +3.1 | 3% | 11% | Turku → Hämeenlinna |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in June, km/h |
|---|---|---|
| 0–25 | NE | +4.5 |
| 25–51 | E | +4.3 |
| 51–76 | E | +3.6 |
| 76–101 | E | +3.6 |
| 101–126 | NE | +3.6 |
| 126–152 | NE | +2.7 |
| 152–172 | NE | +3.2 |
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.