Climate averages 1991–2020

Cardiff weather
in July.

A mild, moderately wet month: the warmest and the joint 5th driest of the year.

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

Average high 19.4°C Daytime mean, July

Average low 13.4°C Night-time mean, July

Rainfall 74 mm 12 days with ≥1 mm

Daylight 16 h Sunrise to sunset, per day

July is a mild month in Cardiff: daytime highs average 19.4°C and nights cool to about 13.4°C. By daytime temperature it is the warmest month of the year.

Expect about 74 mm of rain on roughly 12 days, which makes July a moderately wet month (the joint 5th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 16 h 08 min on an average July day.

The nearest other city in this atlas is Newport (17 km away). In July its highs average 20.4°C, 1.0°C warmer than Cardiff, with 63 mm of rain.

Among the 143 cities listed in the United Kingdom, Cardiff ranks joint 100th of 143 for the warmest July highs and 110th of 143 for the driest July (rainfall, lowest first). The mean July high of those 143 cities is 20.0°C; Cardiff is 0.5°C cooler than that mean.

From July to August, average highs fall by 0.2°C to 19.2°C, and monthly rainfall rises from 74 mm to 87 mm.

The annual picture

July 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	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, selected	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

July 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.