Portsmouth, England
United Kingdom · 208k people · 7 m elevation · Northern Hemisphere
Every month in detail
Thirty-year averages for each calendar month.
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Average high | 46°F (8°C) | 47°F (8°C) | 51°F (10°C) | 55°F (13°C) | 61°F (16°C) | 65°F (19°C) | 69°F (21°C) | 69°F (21°C) | 65°F (18°C) | 58°F (15°C) | 52°F (11°C) | 47°F (9°C) |
| Average low | 39°F (4°C) | 38°F (3°C) | 40°F (5°C) | 43°F (6°C) | 48°F (9°C) | 53°F (12°C) | 57°F (14°C) | 58°F (14°C) | 54°F (12°C) | 50°F (10°C) | 44°F (7°C) | 40°F (4°C) |
| Dew point | 38°F (4°C) | 37°F (3°C) | 39°F (4°C) | 42°F (6°C) | 47°F (8°C) | 52°F (11°C) | 55°F (13°C) | 55°F (13°C) | 52°F (11°C) | 48°F (9°C) | 44°F (6°C) | 40°F (4°C) |
| Rainfall | 2.7 in (69 mm) | 2.1 in (54 mm) | 1.9 in (47 mm) | 1.9 in (49 mm) | 1.9 in (49 mm) | 1.9 in (47 mm) | 2 in (50 mm) | 2.3 in (59 mm) | 2.1 in (54 mm) | 3.1 in (78 mm) | 3.2 in (81 mm) | 3 in (77 mm) |
| Rainy days | 12 | 10 | 10 | 10 | 10 | 10 | 10 | 10 | 9 | 12 | 12 | 12 |
| Snowfall | 0.4 in (1.1 cm) | 0.4 in (1 cm) | 0.3 in (0.7 cm) | 0 in (0.1 cm) | 0 in (0 cm) | 0 in (0 cm) | 0 in (0 cm) | 0 in (0 cm) | 0 in (0 cm) | 0 in (0 cm) | 0 in (0 cm) | 0.2 in (0.6 cm) |
| Sunshine | 134 h | 161 h | 238 h | 307 h | 348 h | 363 h | 371 h | 334 h | 269 h | 206 h | 149 h | 129 h |
Scroll the table sideways for all twelve months.
Projected change, 2031–2050
Model projection, not an observationHow this city’s climate may change, measured against the same models’ own 1995–2014 output. Nothing here affects the match score above.
Change in summer afternoon highs
+2.4°F (+1.3°C)
Models range from +1.7°F (+0.9°C) to +2.8°F (+1.5°C)
Days above 90°F (32°C) a year
0 → 0
- January: +1.8°F (+1.0°C)
- February: +1.2°F (+0.7°C)
- March: +1.2°F (+0.7°C)
- April: +1.6°F (+0.9°C)
- May: +1.9°F (+1.0°C)
- June: +1.4°F (+0.8°C)
- July: +2.5°F (+1.4°C)
- August: +3.2°F (+1.8°C)
- September: +2.0°F (+1.1°C)
- October: +1.7°F (+1.0°C)
- November: +1.4°F (+0.8°C)
- December: +1.7°F (+1.0°C)
- Scenario
- SSP5-8.5 (high emissions)
- Models
- 4 · CMIP6 HighResMIP, downscaled
This is a high-emissions pathway — the upper end of plausible futures, not a central estimate. Changes are measured by each model against its own past output and then applied to the observed record, which cancels each model’s bias but not the genuine uncertainty about how much warming occurs. Where the models disagree widely, the range above is the honest answer.