Daily rainfall, frost and wind for Swansea against the 10-year average — the starting point for any weather delay conversation on site.
Weather delay record
SA1 1NW · 1 Dec 2025 – 31 Dec 2025
Rainfall over this period was 149% of the 10-year average for the same calendar window at this location. Conditions were materially wetter than typical for the time of year. 3 days had gusts at or above 47 mph.
Rainfall vs 10-yr avg
149%
293 mm vs 197 mm typical
Rain days >5mm
16
typical: 12.3
Frost days
1
typical: 2.7
High-wind days
3
gusts ≥ 47 mph
Daily record
| Date | Rain (mm) | Min °C | Max °C | Gust (mph) | Flags |
|---|---|---|---|---|---|
| 1 Dec 2025 | 34.5 | 8.7 | 12.4 | 43 | wet |
| 2 Dec 2025 | 16.6 | 5.7 | 9.2 | 27 | wet |
| 3 Dec 2025 | 8.9 | 4.9 | 9.1 | 21 | wet |
| 4 Dec 2025 | 5.7 | 3.8 | 8.5 | 32 | wet |
| 5 Dec 2025 | 18.8 | 4.0 | 10.6 | 53 | wet · wind |
| 6 Dec 2025 | 12.7 | 9.3 | 11.4 | 41 | wet |
| 7 Dec 2025 | 12.5 | 9.1 | 13.0 | 44 | wet |
| 8 Dec 2025 | 7.4 | 10.7 | 12.0 | 38 | wet |
| 9 Dec 2025 | 44.7 | 10.7 | 14.4 | 58 | wet · wind |
| 10 Dec 2025 | 12.9 | 9.1 | 11.3 | 38 | wet |
| 11 Dec 2025 | 1.1 | 9.5 | 11.7 | 31 | |
| 12 Dec 2025 | 11.6 | 6.6 | 11.5 | 32 | wet |
| 13 Dec 2025 | 0.4 | 6.9 | 10.3 | 27 | |
| 14 Dec 2025 | 4.9 | 9.7 | 11.5 | 31 | |
| 15 Dec 2025 | 43.7 | 8.6 | 11.0 | 31 | wet |
| 16 Dec 2025 | 2.0 | 3.0 | 8.8 | 16 | |
| 17 Dec 2025 | 24.8 | 4.6 | 11.5 | 49 | wet · wind |
| 18 Dec 2025 | 13.7 | 7.8 | 11.6 | 38 | wet |
| 19 Dec 2025 | 6.1 | 8.1 | 9.9 | 28 | wet |
| 20 Dec 2025 | 1.3 | 7.7 | 9.4 | 38 | |
| 21 Dec 2025 | 5.1 | 6.9 | 9.8 | 34 | wet |
| 22 Dec 2025 | 3.2 | 8.2 | 10.4 | 27 | |
| 23 Dec 2025 | 0.0 | 6.1 | 9.8 | 24 | |
| 24 Dec 2025 | 0.0 | 3.1 | 5.8 | 27 | |
| 25 Dec 2025 | 0.0 | 2.8 | 5.7 | 36 | |
| 26 Dec 2025 | 0.0 | 2.1 | 5.3 | 24 | |
| 27 Dec 2025 | 0.0 | 3.5 | 6.8 | 30 | |
| 28 Dec 2025 | 0.0 | 4.7 | 6.4 | 26 | |
| 29 Dec 2025 | 0.0 | 3.5 | 5.5 | 18 | |
| 30 Dec 2025 | 0.0 | 1.8 | 6.4 | 22 | |
| 31 Dec 2025 | 0.0 | -1.7 | 3.6 | 12 | frost |
16 days with rainfall over 5 mm in this period.
Data: ERA5 reanalysis via Open-Meteo, taken at the nearest model grid point to the postcode — not a Met Office station record. Baselines are the mean of the same calendar months over the previous 10 years at this location. Whether conditions meet a contractual test (e.g. JCT “exceptionally adverse weather” or an NEC 1-in-10-year event) is a matter for the contract — this is a factual weather record, not advice.
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