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 63°F 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.

63
63°F max day temperature
5
5 hours of sunshine per day
15
15 days with some rainfall
52
52°F min night temperature
13
13 hours of daylight per day
0
No heat & humidity
3.2
3.2 inches of monthly rainfall
4
4 (Moderate) UV index
61
61°F 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) | Imperial (°F)

More about the UK

How warm is it in Cornwall in September?

Daytime temperatures usually reach 63°F in Newquay, Cornwall in September, falling to 52°F 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 61°F.

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 3.2 inches.

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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