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Caerdydd Weather by Month
Average temperatures, rainfall and humidity for Caerdydd, United Kingdom, month by month, built from OpenWeather’s historical records. Use it to see what a typical Caerdydd month looks like before you travel — then check the live Caerdydd forecast for the days ahead.
Warmest month
July
22°C average high
Coolest month
January
3°C average low
Wettest month
December
128 mm of rain
Driest month
April
60 mm of rain
Average temperature and rainfall in Caerdydd by month
Averages of the daily highs and lows recorded in each month, with total rainfall, mean humidity and mean wind speed.
| Month | Avg high | Avg low | Record low / high | Rainfall | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 8°C | 3°C | -5°C / 14°C | 120 mm | 89% | 17 km/h |
| February | 9°C | 4°C | -5°C / 17°C | 92 mm | 86% | 18 km/h |
| March | 10°C | 4°C | -6°C / 20°C | 92 mm | 83% | 18 km/h |
| April | 13°C | 6°C | -2°C / 24°C | 60 mm | 77% | 17 km/h |
| May | 17°C | 9°C | 1°C / 31°C | 72 mm | 78% | 16 km/h |
| June | 20°C | 12°C | 5°C / 35°C | 62 mm | 79% | 16 km/h |
| July | 22°C | 14°C | 6°C / 34°C | 69 mm | 78% | 15 km/h |
| August | 21°C | 13°C | 7°C / 33°C | 95 mm | 80% | 15 km/h |
| September | 19°C | 12°C | 4°C / 29°C | 79 mm | 83% | 15 km/h |
| October | 15°C | 9°C | 0°C / 23°C | 115 mm | 86% | 16 km/h |
| November | 11°C | 6°C | -4°C / 17°C | 119 mm | 88% | 17 km/h |
| December | 9°C | 5°C | -4°C / 15°C | 128 mm | 89% | 18 km/h |
Best time to visit Caerdydd
The most comfortable time to visit Caerdydd is generally June to August, balancing mild daytime temperatures against the driest stretch of the year. The city has a moderate seasonal swing and rain concentrates around December, totalling about 1,103 mm a year.
Travellers who prefer heat should aim for July, when highs average 22°C. December is the month to avoid if rain would spoil your plans — it averages 128 mm, roughly 2× the rainfall of the driest month (April).
Source: OpenWeather historical and statistical weather data. Values are long-term averages, not a forecast — see the Caerdydd forecast for what is happening now.