Cornwall in September
7.5out of 10
Yes, a good time to go
Mild: highs around 21°C. Frequent rain: about 11 rainy days.
21°CAvg high
11°CAvg low
11Rainy days (92 mm)
12:18 hDaylight
06:44Sunrise · 19:02 Sunset
Why this score
- Mild: highs around 21°C
- Frequent rain: about 11 rainy days
What to wear and pack
- Layers you can add or remove
- A light jacket for cooler evenings
- Rain jacket or compact umbrella
How reliable is the forecast?
Rainfall in September is fairly consistent from year to year (2.9 days). Averages cover 30 years (1991–2020). Individual days can differ a lot.
Year at a glance
Weather by month
| Month | Avg high | Avg low | Rainfall | Rainy days | Humidity | Sunshine | Score |
|---|---|---|---|---|---|---|---|
| January | -3°C | -12°C | 73 mm | 12 | – | – | 3.5 |
| February | -2°C | -11°C | 62 mm | 10 | – | – | 3.7 |
| March | 4°C | -6°C | 76 mm | 11 | – | – | 4.2 |
| April | 12°C | 2°C | 101 mm | 12 | – | – | 5.7 |
| May | 20°C | 9°C | 98 mm | 13 | – | – | 6.9 |
| June | 24°C | 13°C | 105 mm | 12 | – | – | 7.3 |
| July | 26°C | 16°C | 100 mm | 13 | – | – | 7.3 |
| August | 25°C | 16°C | 94 mm | 12 | – | – | 7.5 |
| September | 21°C | 11°C | 92 mm | 11 | – | – | 7.5 |
| October | 14°C | 5°C | 104 mm | 12 | – | – | 6.0 |
| November | 7°C | -1°C | 84 mm | 12 | – | – | 4.8 |
| December | 0°C | -7°C | 83 mm | 12 | – | – | 3.4 |
Frequently asked questions
How hot is Cornwall in September?
Daytime highs average 21°C and nights about 11°C.
When is the best time to visit Cornwall?
The best months are August, September, June, July.