Key Largo weather in September 2025

Q: How hot is it in Key Largo in September?

Daytime temperatures usually reach 32°C in Key Largo in September with very high heat and humidity, falling to 23°C at night.

Q: How sunny is it in Key Largo in September?

There are normally 9 hours of bright sunshine each day in Key Largo in September - that's 69% of daylight hours.

Q: How warm is the sea around Key Largo in September?

The average sea temperature around Key Largo in September is 29°C.

Q: Does it rain in Key Largo in September?

There are usually 17 days with some rain in Key Largo in September and the average monthly rainfall is 213mm.

Q: What is the chance of a cyclone in Key Largo in September?

On average less than 1 day in September in Key Largo is likely to be affected by the passage of one or more tropical storms.

Expect 90°F daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Key Largo in September. Check more long-term weather averages for Key Largo in September before you book your next holiday to Florida in 2025/2026.

90
90°F max day temperature
9
9 hours of sunshine per day
17
17 days with some rainfall
73
73°F min night temperature
12
12 hours of daylight per day
VH
Very High heat & humidity
8.4
8.4 inches of monthly rainfall
10
10 (Very High) UV index
84
84°F sea temperature

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Destination

The September weather guide for Florida (Key Largo) 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.

Metric (°C) | Imperial (°F)

More about Florida

How hot is it in Key Largo in September?

Daytime temperatures usually reach 90°F in Key Largo in September with very high heat and humidity, falling to 73°F at night.

How sunny is it in Key Largo in September?

There are normally 9 hours of bright sunshine each day in Key Largo in September - that's 69% of daylight hours.

How warm is the sea around Key Largo in September?

The average sea temperature around Key Largo in September is 84°F.

Does it rain in Key Largo in September?

There are usually 17 days with some rain in Key Largo in September and the average monthly rainfall is 8.4 inches.

What is the chance of a hurricane in Key Largo in September?

On average less than 1 day in September in Key Largo is likely to be affected by the passage of one or more tropical storms.

Key Largo September sunrise & sunset times

Browse the sunrise and sunset times for Key Largo in September 2025. Select a month to view Key Largo sunrise and sunset times for the next 12 months.

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Date	Sunrise times	Sunset times
Monday, 1st September 2025	06:03	18:40
Monday, 15th September 2025	06:08	18:25
Tuesday, 30th September 2025	06:14	18:09

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Florida - quick facts
Flight time^✝	9.5 hours
Time difference	UK -5 to -6 hours
Language(s)	English
Currency	US Dollar
Electricity	A + B plug (120V)
Driving side	Right
Visa^✝	Yes
Why visit?	Beaches Culture Nature Nightlife
Tourist info	Visit Florida