Climate averages 1991–2020

Cardiff weather
in January.

A cold, wet month: the coolest and the 9th driest of the year.

Long-term climate patterns, not a forecast for a particular trip.

Average high 7.4°C Daytime mean, January

Average low 3.3°C Night-time mean, January

Rainfall 95 mm 15 days with ≥1 mm

Daylight 8 h Sunrise to sunset, per day

January is a cold month in Cardiff: daytime highs average 7.4°C and nights cool to about 3.3°C. By daytime temperature it is the coolest month of the year.

Expect about 95 mm of rain on roughly 15 days, which makes January a wet month (the 9th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 8 h 24 min on an average January day.

The nearest other city in this atlas is Newport (17 km away). In January its highs average 7.6°C, about as warm as Cardiff, with 77 mm of rain.

Among the 143 cities listed in the United Kingdom, Cardiff ranks joint 20th of 143 for the warmest January highs and joint 130th of 143 for the driest January (rainfall, lowest first). The mean January high of those 143 cities is 6.9°C; Cardiff is 0.6°C warmer than that mean.

From January to February, average highs rise by 0.3°C to 7.8°C, and monthly rainfall falls from 95 mm to 75 mm.

The annual picture

January in context

30-year average

Average highAverage low°C

Monthly rainfall

Average total · mm

Averages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated

Every month, side by side

Cardiff climate table

1991–2020

Monthly climate averages for Cardiff, 1991–2020
Month	Average highHigh / low	Average low	Rainfall mm/month	Rain days ≥1 mm/day	Daylight hours/dayDaylight h/day
January, selected	7.4°C3.3°C	3.3°C	95	14.5	8.48 h
February	7.8°C3.0°C	3.0°C	75	11.3	9.910 h
March	9.6°C3.9°C	3.9°C	68	11.7	11.812 h
April	12.2°C5.5°C	5.5°C	70	11.6	13.814 h
May	15.2°C8.5°C	8.5°C	73	12.3	15.616 h
June	17.7°C11.4°C	11.4°C	71	11.0	16.517 h
July	19.4°C13.4°C	13.4°C	74	11.6	16.116 h
August	19.2°C13.5°C	13.5°C	87	12.3	14.615 h
September	17.2°C11.5°C	11.5°C	74	11.0	12.713 h
October	13.8°C9.0°C	9.0°C	106	14.0	10.711 h
November	10.3°C6.1°C	6.1°C	102	14.5	8.99 h
December	7.9°C3.9°C	3.9°C	107	13.7	7.98 h

Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.

Compare places

January in nearby cities

Distance from Cardiff

Read the numbers correctly

Climate, not a promise.

These patterns help compare months. They cannot tell you the weather on a specific day of your trip.

Sources, method and limits

How these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Cardiff) is explained once on the Cardiff year overview and on the Sources, method and limits page.