Nasjonal sykkelrute 4, stage 2: Flå → Geilo
On stage 2 (Flå → Geilo, 115 km) the best month is June: 61% of days were dry with highs of 10–30 °C; the wind barely favours either direction (1.6 km/h on average; ERA5 2006–2025, 9:00–18:00).
← Nasjonal sykkelrute 4 (Whole route)
Weather by month
| Month | Good days | Rain days ≥ 1 mm | Rain, mm | Avg high | Days ≥ 30 °C | Days < 10 °C | Daylight, h |
|---|---|---|---|---|---|---|---|
| January | 0% | 24% | 66 | -5 °C | 0% | 100% | 6.5 † |
| February | 0% | 20% | 47 | -3 °C | 0% | 100% | 9.0 † |
| March | 1% | 20% | 50 | 1 °C | 0% | 99% | 11.6 |
| April | 15% | 21% | 48 | 5 °C | 0% | 85% | 14.5 |
| May | 40% | 33% | 77 | 11 °C | 0% | 50% | 17.2 |
| June | 61% | 36% | 99 | 15 °C | 0% | 10% | 19.0 |
| July | 57% | 43% | 125 | 17 °C | 0% | 2% | 18.3 |
| August | 59% | 40% | 113 | 15 °C | 0% | 3% | 15.7 |
| September | 49% | 28% | 94 | 11 °C | 0% | 37% | 12.8 |
| October | 7% | 25% | 82 | 5 °C | 0% | 92% | 9.9 † |
| November | 0% | 24% | 73 | 0 °C | 0% | 99% | 7.2 † |
| December | 0% | 25% | 69 | -4 °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 Flå → Geilo, km/h | Headwind > 15 km/h, Flå → Geilo | Headwind > 15 km/h, Geilo → Flå | Better way |
|---|---|---|---|---|
| January | −2.8 | 5% | 0% | Geilo → Flå |
| February | −2.2 | 3% | 0% | Geilo → Flå |
| March | −2.6 | 6% | 0% | Geilo → Flå |
| April | −2.4 | 6% | 1% | Geilo → Flå |
| May | −1.8 | 4% | 1% | either |
| June | −1.6 | 4% | 1% | either |
| July | −0.7 | 3% | 0% | either |
| August | −0.4 | 2% | 0% | either |
| September | −1.4 | 5% | 1% | either |
| October | −1.2 | 3% | 1% | either |
| November | −1.8 | 3% | 0% | either |
| December | −3.2 | 4% | 0% | Geilo → Flå |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in June, km/h |
|---|---|---|
| 135–161 | NW | −0.1 |
| 161–186 | NW | +0.1 |
| 186–211 | W | −2.4 |
| 211–236 | SW | −2.8 |
| 236–250 | SW | −3.3 |
Other stages
- Asker → Flå 135 km
- Flå → Geilo 115 km
- Geilo → near Lærdalsøyri 136 km
- near Lærdalsøyri → Ål 155 km
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.