Cornwall weather in September 2025

Q: How warm is it in Cornwall in September?

Daytime temperatures usually reach 17°C in Newquay, Cornwall in September, falling to 11°C at night.

Q: How sunny is it in Cornwall in September?

There are normally 5 hours of bright sunshine each day in Newquay, Cornwall in September - that's 41% of daylight hours.

Q: How warm is the sea around Cornwall in September?

The average sea temperature around Newquay, Cornwall in September is 16°C.

Q: Does it rain in Cornwall in September?

There are usually 15 days with some rain in Newquay, Cornwall in September and the average monthly rainfall is 81mm.

Expect 17°C daytime maximum temperatures in the shade with on average 5 hours of sunshine per day in Cornwall in September. Check more long-term weather averages for Cornwall in September before you book your next holiday to Cornwall in 2025/2026.

17
17°C max day temperature
5
5 hours of sunshine per day
15
15 days with some rainfall
11
11°C min night temperature
13
13 hours of daylight per day
0
No heat & humidity
81
81 mm of monthly rainfall
4
4 (Moderate) UV index
16
16°C sea temperature

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The September weather guide for Cornwall (Newquay) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Top Cornwall destinations

Below are average maximum temperatures at popular countries, regions and places in Cornwall in September. Select a holiday destination to see more weather parameters.

Metric (°C / mm) | Imperial (°F / inches)

More about the UK

How warm is it in Cornwall in September?

Daytime temperatures usually reach 17°C in Newquay, Cornwall in September, falling to 11°C at night.

How sunny is it in Cornwall in September?

There are normally 5 hours of bright sunshine each day in Newquay, Cornwall in September - that's 41% of daylight hours.

How warm is the sea around Cornwall in September?

The average sea temperature around Newquay, Cornwall in September is 16°C.

Does it rain in Cornwall in September?

There are usually 15 days with some rain in Newquay, Cornwall in September and the average monthly rainfall is 81mm.

Cornwall September sunrise & sunset times

Browse the sunrise and sunset times for Cornwall in September 2025. Select a month to view Cornwall sunrise and sunset times for the next 12 months. The Cornwall sunrise and sunset times shown below are for Newquay.

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