Hertfordshire weather in September 2025

Q: How hot is it in Hertfordshire in September?

Daytime temperatures usually reach 19°C in Watford, Hertfordshire in September, falling to 10°C at night.

Q: How sunny is it in Hertfordshire in September?

There are normally 5 hours of bright sunshine each day in Watford, Hertfordshire in September - that's 37% of daylight hours.

Q: Does it rain in Hertfordshire in September?

There are usually 12 days with some rain in Watford, Hertfordshire in September and the average monthly rainfall is 55mm.

Expect 66°F daytime maximum temperatures in the shade with on average 5 hours of sunshine per day in Hertfordshire in September. Check more long-term weather averages for Hertfordshire in September before you book your next holiday to Hertfordshire in 2025/2026.

66
66°F max day temperature
5
5 hours of sunshine per day
12
12 days with some rainfall
50
50°F min night temperature
13
13 hours of daylight per day
0
No heat & humidity
2.2
2.2 inches of monthly rainfall
4
4 (Moderate) UV index

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The September weather guide for Hertfordshire (Watford) 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.

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Metric (°C) | Imperial (°F)

More about the UK

How hot is it in Hertfordshire in September?

Daytime temperatures usually reach 66°F in Watford, Hertfordshire in September, falling to 50°F at night.

How sunny is it in Hertfordshire in September?

There are normally 5 hours of bright sunshine each day in Watford, Hertfordshire in September - that's 37% of daylight hours.

Does it rain in Hertfordshire in September?

There are usually 12 days with some rain in Watford, Hertfordshire in September and the average monthly rainfall is 2.2 inches.

Hertfordshire September sunrise & sunset times

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

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