National Cycle Network Route 4, stage 1: London → Reading
On stage 1 (London → Reading, 116 km) the best month is September: 80% of days were dry with highs of 10–30 °C, and riding Reading → London meant an average tailwind of 3.9 km/h (ERA5 2006–2025, 9:00–18:00).
← National Cycle Network Route 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 | 16% | 19% | 58 | 7 °C | 0% | 76% | 8.3 † |
| February | 25% | 21% | 51 | 8 °C | 0% | 69% | 9.9 † |
| March | 48% | 22% | 48 | 10 °C | 0% | 43% | 11.7 |
| April | 71% | 22% | 41 | 14 °C | 0% | 13% | 13.8 |
| May | 73% | 26% | 59 | 17 °C | 0% | 2% | 15.6 |
| June | 79% | 20% | 58 | 20 °C | 1% | 0% | 16.6 |
| July | 75% | 23% | 61 | 22 °C | 2% | 0% | 16.2 |
| August | 76% | 22% | 61 | 21 °C | 2% | 0% | 14.6 |
| September | 80% | 20% | 47 | 19 °C | 0% | 0% | 12.6 |
| October | 76% | 21% | 66 | 15 °C | 0% | 3% | 10.6 † |
| November | 46% | 22% | 67 | 11 °C | 0% | 40% | 8.8 † |
| December | 25% | 20% | 60 | 8 °C | 0% | 64% | 7.9 † |
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 London → Reading, km/h | Headwind > 15 km/h, London → Reading | Headwind > 15 km/h, Reading → London | Better way |
|---|---|---|---|---|
| January | −6.1 | 23% | 4% | Reading → London |
| February | −4.6 | 23% | 8% | Reading → London |
| March | −2.6 | 19% | 10% | Reading → London |
| April | −0.4 | 13% | 11% | either |
| May | −2.2 | 17% | 8% | Reading → London |
| June | −3.2 | 17% | 6% | Reading → London |
| July | −6.0 | 20% | 2% | Reading → London |
| August | −6.2 | 21% | 2% | Reading → London |
| September | −3.9 | 17% | 5% | Reading → London |
| October | −4.0 | 18% | 6% | Reading → London |
| November | −4.8 | 20% | 4% | Reading → London |
| December | −6.3 | 25% | 4% | Reading → London |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–25 | W | −4.6 |
| 25–51 | SW | −5.0 |
| 51–76 | NW | −1.3 |
| 76–101 | W | −4.2 |
| 101–116 | SW | −5.0 |
Other stages
- London → Reading 116 km
- Reading → Bath 128 km
- Bath → Pontypridd 129 km
- Pontypridd → Carmarthen 126 km
- Carmarthen → Fishguard 147 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.