NCN National Route 1: which way and when to ride
The best month for NCN National Route 1 is September: 80% of days were dry with highs of 10–30 °C. In September the wind barely favours either direction — on average 0.7 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 | 11% | 21% | 55 | 7 °C | 0% | 82% | 8.2 † |
| February | 17% | 21% | 51 | 8 °C | 0% | 78% | 9.8 † |
| March | 36% | 20% | 46 | 9 °C | 0% | 57% | 11.7 |
| April | 61% | 19% | 36 | 12 °C | 0% | 28% | 13.8 |
| May | 73% | 25% | 59 | 15 °C | 0% | 4% | 15.7 |
| June | 78% | 22% | 59 | 18 °C | 0% | 0% | 16.8 |
| July | 74% | 26% | 65 | 21 °C | 1% | 0% | 16.4 |
| August | 77% | 23% | 69 | 21 °C | 0% | 0% | 14.7 |
| September | 80% | 20% | 54 | 18 °C | 0% | 0% | 12.6 |
| October | 74% | 24% | 69 | 15 °C | 0% | 3% | 10.5 † |
| November | 45% | 22% | 64 | 10 °C | 0% | 42% | 8.6 † |
| December | 19% | 20% | 62 | 8 °C | 0% | 71% | 7.7 † |
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 Ipswich → King's Lynn, km/h | Headwind > 15 km/h, Ipswich → King's Lynn | Headwind > 15 km/h, King's Lynn → Ipswich | Better way |
|---|---|---|---|---|
| January | +1.4 | 16% | 22% | either |
| February | +1.4 | 18% | 22% | either |
| March | +0.3 | 18% | 19% | either |
| April | −0.1 | 17% | 16% | either |
| May | −0.2 | 17% | 16% | either |
| June | +0.4 | 14% | 15% | either |
| July | +1.3 | 11% | 17% | either |
| August | +1.1 | 14% | 18% | either |
| September | +0.7 | 15% | 17% | either |
| October | +2.0 | 15% | 22% | Ipswich → King's Lynn |
| November | +1.7 | 17% | 22% | either |
| December | +2.3 | 16% | 24% | Ipswich → King's Lynn |
Along the route (sections of about 25 km)
| km | Heading | Tailwind in September, km/h |
|---|---|---|
| 0–1 | W | −4.4 |
| 1–26 | N | +4.4 |
| 26–51 | E | +5.2 |
| 51–77 | NE | +5.1 |
| 77–102 | NE | +5.4 |
| 102–127 | N | +4.3 |
| 127–152 | N | +1.6 |
| 152–177 | NW | −2.8 |
| 177–203 | NW | −1.8 |
| 203–228 | NW | −3.5 |
| 228–253 | N | +0.5 |
| 253–279 | W | −5.4 |
| 279–304 | SW | −4.4 |
| 304–307 | S | −2.5 |
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.