Cardiff, United Kingdom Climate & Monthly Averages
Cardiff has an oceanic climate. July is the hottest month, averaging 69° by day; January is the coldest at 46°.
How weather changes through the year in Cardiff
Cardiff has an oceanic climate. Average highs run from 46°F (8°C) in January to 69°F (20°C) in July, and the city records roughly 171 days of measurable precipitation a year.
Cardiff climate quick facts
- Hottest month: July - highs near 69°F (20°C)
- Coldest month: January - highs near 46°F (8°C)
- Decade extremes (2015-2024): 91°F (33°C) high · 22°F (-6°C) low
- Wettest month: December (17 rainy days) · Sunniest: June (11.7 h sun/day)
- Climate type: oceanic
- Annual swing: 12°C between the average warmest and coolest month · day to night: 6°C
- Snow: about 2 days a year
- Average humidity: 82%
Temperatures, rain and sunshine
Snowfall is rare but not unheard of. January sits at the other end of the year: 46°F (8°C) by day, 37°F (3°C) at night. Warmth peaks in July: highs of 69°F (20°C), lows of 56°F (13°C). The wettest month is December (5.6 inches (143 mm) across 17 days) and the driest June.
Days and nights are about 6°C apart on average - narrower than all but 10% of the 3496 cities in our dataset. Sunshine averages 7.7 hours a day over the year - duller than about 89% of the cities we track, peaking in June at 11.7 hours. Relative humidity averages 82% across the year, more humid than 92% of the 3496 cities in our dataset.
The gridded 2015-2024 daily record for this location tops out at 91°F (33°C) and bottoms at 22°F (-6°C) - decade extremes, not all-time station records.
Where Cardiff sits among other climates
- Cardiff sits close to the middle of our dataset on most measures: 52°F (11°C) as an annual average, 47.8 inches (1215 mm) of precipitation and 7.7 hours of sun a day.
These comparisons use the same ten-year window for every city in the dataset.
Monthly climate table
| Month | High | Low | Rain days | Precipitation | Sunshine | Daylight | Wet-day chance | Humidity |
|---|---|---|---|---|---|---|---|---|
| January | 46° | 37° | 15 | 4.0 in | 4.1 h/day | 8.3 h | 50% | 87% |
| February | 48° | 38° | 14 | 4.2 in | 5.3 h/day | 9.9 h | 48% | 84% |
| March | 50° | 39° | 16 | 4.2 in | 6.9 h/day | 11.7 h | 52% | 81% |
| April | 55° | 41° | 11 | 2.6 in | 9.8 h/day | 13.8 h | 35% | 76% |
| May | 61° | 47° | 12 | 3.3 in | 11.1 h/day | 15.6 h | 40% | 77% |
| June | 66° | 53° | 12 | 2.6 in | 11.7 h/day | 16.6 h | 41% | 76% |
| July | 69° | 56° | 15 | 3.4 in | 11.4 h/day | 16.2 h | 47% | 77% |
| August | 68° | 56° | 15 | 4.0 in | 10.0 h/day | 14.6 h | 48% | 80% |
| September | 64° | 53° | 13 | 4.1 in | 8.5 h/day | 12.5 h | 43% | 82% |
| October | 58° | 48° | 16 | 5.4 in | 6.3 h/day | 10.5 h | 51% | 84% |
| November | 51° | 43° | 15 | 4.4 in | 4.4 h/day | 8.8 h | 51% | 87% |
| December | 49° | 41° | 17 | 5.6 in | 3.3 h/day | 7.9 h | 55% | 89% |
Cardiff month by month
Each card shows the average high and low. The bar places that month between Cardiff's coldest night and warmest afternoon.
January
- Rain
- 15 days
- Sunshine
- 4.1 h
- Daylight
- 8.3 h
February
- Rain
- 14 days
- Sunshine
- 5.3 h
- Daylight
- 9.9 h
March
- Rain
- 16 days
- Sunshine
- 6.9 h
- Daylight
- 11.7 h
April
- Rain
- 11 days
- Sunshine
- 9.8 h
- Daylight
- 13.8 h
May
- Rain
- 12 days
- Sunshine
- 11.1 h
- Daylight
- 15.6 h
June
- Rain
- 12 days
- Sunshine
- 11.7 h
- Daylight
- 16.6 h
July
- Rain
- 15 days
- Sunshine
- 11.4 h
- Daylight
- 16.2 h
August
- Rain
- 15 days
- Sunshine
- 10.0 h
- Daylight
- 14.6 h
September
- Rain
- 13 days
- Sunshine
- 8.5 h
- Daylight
- 12.5 h
October
- Rain
- 16 days
- Sunshine
- 6.3 h
- Daylight
- 10.5 h
November
- Rain
- 15 days
- Sunshine
- 4.4 h
- Daylight
- 8.8 h
December
- Rain
- 17 days
- Sunshine
- 3.3 h
- Daylight
- 7.9 h
Looking for warmer alternatives? Browse warm places by month, or compare Cardiff's coolest part of the year: January, February, December.
A season-by-season guide to Cardiff
Spring (March through May)
Through spring, Cardiff stays on the cool side of mild: 55°F (13°C) by day, 43°F (6°C) after dark, and rain falls on around 39 of the 90 days.
Summer (June through August)
Summer in Cardiff stays on the cool side of mild, with daytime highs averaging 67°F (20°C) and nights around 55°F (13°C); rain falls on around 42 of the 90 days. Daylight is generous - around 11.0 hours of sun a day.
Fall (September through November)
Fall in Cardiff is crisp but comfortable, with daytime highs averaging 58°F (14°C) and nights around 48°F (9°C); rain falls on around 44 of the 90 days.
Winter (December through February)
Through winter, Cardiff is brisk and cold: 47°F (9°C) by day, 38°F (4°C) after dark, and rain falls on around 46 of the 90 days.
Questions people ask about Cardiff's climate
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The most useful weather window for Cardiff
Best time to visit Cardiff
The best time to visit Cardiff is generally April to September, when warm days, manageable rainfall and plenty of daylight line up. Daytime temperatures in that window sit near 64°F (18°C), with rain on about 13 days a month. For the same question asked the other way round, see where else is warm in April.
What to pack
Pack for Cardiff with a warm jacket and layers for the cooler season and proper waterproofs rather than an umbrella - wet days are the norm here. Note the gap between afternoon and night: July pairs 69°F (20°C) with 56°F (13°C).
Cardiff temperature extremes in the 2015–2024 dataset
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need another precipitation unit? Use the rainfall converter.