| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean daily maximum °C (°F) | 8.2 (46.8) |
8.4 (47.1) |
10.2 (50.4) |
12.9 (55.2) |
15.9 (60.6) |
18.5 (65.3) |
20.2 (68.4) |
20.0 (68.0) |
18.1 (64.6) |
14.7 (58.5) |
11.2 (52.2) |
8.7 (47.7) |
13.9 (57.0) |
| Mean daily minimum °C (°F) | 3.1 (37.6) |
3.0 (37.4) |
4.2 (39.6) |
5.8 (42.4) |
8.6 (47.5) |
11.5 (52.7) |
13.4 (56.1) |
13.5 (56.3) |
11.5 (52.7) |
9.0 (48.2) |
5.9 (42.6) |
3.7 (38.7) |
7.8 (46.0) |
| Average rainfall mm (inches) | 100.5 (3.96) |
76.3 (3.00) |
70.7 (2.78) |
63.0 (2.48) |
64.1 (2.52) |
66.2 (2.61) |
80.6 (3.17) |
97.7 (3.85) |
81.5 (3.21) |
112.8 (4.44) |
111.1 (4.37) |
118.8 (4.68) |
1,043.2 (41.07) |
| Average rainy days (≥ 1 mm) | 15.2 | 12.1 | 11.9 | 10.8 | 10.6 | 10.1 | 11.2 | 13.2 | 11.7 | 15.1 | 15.9 | 15.7 | 153.4 |
| Mean monthly sunshine hours | 56.0 | 85.0 | 128.0 | 181.8 | 226.3 | 217.1 | 220.2 | 189.8 | 160.5 | 108.8 | 66.3 | 52.1 | 1,691.8 |
| Source: Met Office[1] | |||||||||||||
- ^ "St-Athan (Vale of Glamorgan) UK climate averages - Met Office". Met Office. Retrieved July 6, 2024.