Daily rainfall, frost and wind for Portsmouth against the 10-year average — the starting point for any weather delay conversation on site.
Weather delay record
PO1 2EG · 1 Jan 2026 – 31 Jan 2026
Rainfall over this period was 209% of the 10-year average for the same calendar window at this location. Conditions were materially wetter than typical for the time of year. 4 days had gusts at or above 47 mph.
Rainfall vs 10-yr avg
209%
173 mm vs 83 mm typical
Rain days >5mm
12
typical: 5.7
Frost days
7
typical: 5.7
High-wind days
4
gusts ≥ 47 mph
Daily record
| Date | Rain (mm) | Min °C | Max °C | Gust (mph) | Flags |
|---|---|---|---|---|---|
| 1 Jan 2026 | 0.0 | -1.2 | 6.5 | 27 | frost |
| 2 Jan 2026 | 2.2 | 0.1 | 4.0 | 26 | |
| 3 Jan 2026 | 0.0 | -1.1 | 3.4 | 27 | frost |
| 4 Jan 2026 | 0.0 | -2.5 | 3.4 | 18 | frost |
| 5 Jan 2026 | 0.0 | -1.6 | 2.3 | 20 | frost |
| 6 Jan 2026 | 2.5 | -3.7 | 5.9 | 28 | frost |
| 7 Jan 2026 | 7.4 | 2.0 | 6.5 | 36 | wet |
| 8 Jan 2026 | 17.6 | 3.5 | 9.8 | 43 | wet |
| 9 Jan 2026 | 2.3 | 2.8 | 6.8 | 48 | wind |
| 10 Jan 2026 | 0.0 | -1.3 | 4.5 | 25 | frost |
| 11 Jan 2026 | 5.8 | 0.8 | 10.1 | 47 | wet · wind |
| 12 Jan 2026 | 1.7 | 9.7 | 11.3 | 44 | |
| 13 Jan 2026 | 11.5 | 7.9 | 10.4 | 32 | wet |
| 14 Jan 2026 | 5.9 | 0.0 | 9.5 | 29 | wet · frost |
| 15 Jan 2026 | 18.9 | 6.2 | 9.2 | 46 | wet |
| 16 Jan 2026 | 4.5 | 4.1 | 9.1 | 26 | |
| 17 Jan 2026 | 2.1 | 6.9 | 9.2 | 21 | |
| 18 Jan 2026 | 4.6 | 6.5 | 10.3 | 19 | |
| 19 Jan 2026 | 2.1 | 8.2 | 9.8 | 24 | |
| 20 Jan 2026 | 6.3 | 7.5 | 9.2 | 50 | wet · wind |
| 21 Jan 2026 | 13.9 | 6.3 | 10.0 | 51 | wet · wind |
| 22 Jan 2026 | 6.7 | 7.3 | 9.7 | 34 | wet |
| 23 Jan 2026 | 7.1 | 7.1 | 9.0 | 43 | wet |
| 24 Jan 2026 | 4.6 | 7.2 | 8.6 | 46 | |
| 25 Jan 2026 | 4.2 | 5.0 | 7.6 | 27 | |
| 26 Jan 2026 | 2.0 | 4.3 | 7.8 | 34 | |
| 27 Jan 2026 | 20.4 | 7.0 | 10.2 | 47 | wet |
| 28 Jan 2026 | 1.0 | 4.4 | 8.9 | 18 | |
| 29 Jan 2026 | 2.1 | 4.8 | 8.0 | 33 | |
| 30 Jan 2026 | 13.9 | 6.6 | 10.0 | 39 | wet |
| 31 Jan 2026 | 1.9 | 6.9 | 9.6 | 25 |
12 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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