Cardiff weather in September

Long-run climate averages for Cardiff, Wales in September, plus what the forecast models say for the days ahead.

September at a glance

In September, Cardiff averages 19°C by day and 12°C at night. The wettest month is usually October.

September in Cardiff averages a daytime high of 19°C and an overnight low of 12°C, which reads as mild for this part of the world. Across the whole year Cardiff sees roughly 1510 mm of precipitation.

Climate averages tell you what to pack. They do not tell you what next Tuesday looks like — for that, see the live Cardiff forecast with every model compared and how much they currently agree.

Cardiff weather by month

what to expect in Cardiff through the year

Here is Cardiff's typical weather in each month: the average daytime high and overnight low in °C, how each month feels, and the wettest month marked. Use it to plan any trip to Cardiff by season.

Jan

8°

2°

Cool

Feb

10°

4°

Cool

Mar

10°

5°

Cool

Apr

12°

6°

Cool

May

17°

9°

Mild

Jun

20°

11°

Mild

Jul

19°

12°

Mild

Aug

20°

13°

Mild

Sep

19°

12°

Mild

Oct

15°

9°

Mild

Wettest

Nov

11°

5°

Cool

Dec

10°

6°

Cool

Common questions

How warm is Cardiff in September?

Cardiff averages a daytime high of 19°C in September, with overnight lows around 12°C. These are long-run climate averages, not a forecast — for the actual days ahead see the live model comparison.

Is September a good time to visit Cardiff?

The most comfortable time to visit Cardiff is usually May, June, July and August, when daytime highs sit in the pleasant 16-26°C range and the heaviest October rain is behind you.

Does it rain a lot in Cardiff in September?

The wettest month in Cardiff is usually October. Across the year the city sees roughly 1510 mm of precipitation.

Cardiff in other months

January February March April May June July August October November December

More about Cardiff

Cardiff live forecast Best time to visit Cardiff Which forecast is most accurate in United Kingdom?