Cykelspåret (7): which way and when to ride
The best month for Cykelspåret (7) is September: 81% of days were dry with highs of 10–30 °C. In September, riding near Söderköping → Trosa meant an average tailwind of 4.1 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% | 18% | 48 | 1 °C | 0% | 100% | 7.0 † |
| February | 0% | 14% | 33 | 1 °C | 0% | 100% | 9.2 † |
| March | 7% | 14% | 33 | 4 °C | 0% | 93% | 11.6 |
| April | 33% | 14% | 30 | 9 °C | 0% | 65% | 14.3 |
| May | 69% | 20% | 48 | 14 °C | 0% | 16% | 16.8 |
| June | 77% | 23% | 59 | 18 °C | 0% | 0% | 18.4 |
| July | 75% | 25% | 70 | 21 °C | 0% | 0% | 17.7 |
| August | 73% | 27% | 78 | 20 °C | 0% | 0% | 15.4 |
| September | 81% | 18% | 54 | 16 °C | 0% | 1% | 12.7 |
| October | 46% | 19% | 63 | 10 °C | 0% | 42% | 10.1 † |
| November | 7% | 20% | 55 | 6 °C | 0% | 91% | 7.6 † |
| December | 1% | 19% | 51 | 3 °C | 0% | 99% | 6.3 † |
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 Söderköping → Trosa, km/h | Headwind > 15 km/h, near Söderköping → Trosa | Headwind > 15 km/h, Trosa → near Söderköping | Better way |
|---|---|---|---|---|
| January | +4.7 | 6% | 22% | near Söderköping → Trosa |
| February | +3.8 | 7% | 17% | near Söderköping → Trosa |
| March | +3.3 | 7% | 16% | near Söderköping → Trosa |
| April | +1.9 | 7% | 12% | either |
| May | +1.4 | 6% | 8% | either |
| June | +3.4 | 5% | 11% | near Söderköping → Trosa |
| July | +4.0 | 4% | 13% | near Söderköping → Trosa |
| August | +4.3 | 4% | 14% | near Söderköping → Trosa |
| September | +4.1 | 6% | 19% | near Söderköping → Trosa |
| October | +4.8 | 7% | 20% | near Söderköping → Trosa |
| November | +4.4 | 8% | 20% | near Söderköping → Trosa |
| December | +6.4 | 4% | 26% | near Söderköping → Trosa |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–1 | NW | +0.5 |
| 1–27 | NE | +3.5 |
| 27–52 | NE | +4.5 |
| 52–77 | E | +4.1 |
| 77–102 | NE | +4.4 |
| 102–118 | NE | +4.0 |
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.