Weather in Grenada in September

How September compares

September is the 1st warmest month of the year in Grenada and ranks 42nd of 134 destinations we compare for September - see where else is hot in September. Against London's average high of 18.6°C in September, Grenada is 9.9°C warmer by day and 15.1°C warmer at night.

Daytime and night-time in September

The typical September day in Grenada peaks at 28.5°C, but that is an average: the warmest 10% of days reach 29.4°C or more. About 100% of days top 25°C and 1 in 24 pass 30°C. Nights average 26.3°C; one night in ten drops to 25.3°C or lower, so pack a layer for evenings. Between 1991 and 2020 the hottest September day here reached 31.1°C (2019-09-13) and the coldest night 24.5°C (1992-09-22).

Rain in September

Wet (more than 8 rainy days): about 21 days with 1 mm or more, 139 mm in total. Year to year it varies a lot - the wettest September was 2004 with 215 mm, the driest 2012 with 83 mm. Humidity averages 81%, which makes the heat feel heavier than the thermometer suggests.

Sea temperature in September

The sea averages 29.2°C - warm enough to swim (22°c+). Depending on the year it ranges from 28.6°C to 29.6°C. This is the warmest the sea gets here all year.

Sunshine and daylight

Around 4.7 hours of sunshine a day (estimated from cloud cover), 12.1 hours of daylight: the sun rises about 05:56 and sets about 18:08 local time in mid-September. Average cloud cover is 61%.

Is September a good time to visit Grenada?

It is a reasonable choice: hot days but expect showers. The best months for Grenada on our scoring are March, February, April; months averaging 25°C or more: Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec.

Hot days, with little relief at night

September ranks as Grenada's warmest month, but the humidity is more useful for planning than that ranking alone. At 81%, it makes this a month for loose, breathable clothing and an unhurried pace, especially around midday. Average daytime highs of 28.5°C do not suggest extreme temperatures, yet average night lows of 26.3°C mean evenings offer limited relief. Air conditioning is worth prioritising if warm bedrooms affect your sleep. Pack light clothes for evenings as well as daytime, rather than assuming you will need a jumper after sunset. This suits travellers comfortable with persistent warmth more than those who like cool nights.

Plan around rain, not uninterrupted sunshine

With about 21 rainy days, wet weather needs to be part of your plans rather than treated as an unlikely interruption. That does not establish how long rain will last on any particular day, so avoid assuming it will always be a brief shower. Sunshine averages about 4.7 hours within 12.1 hours of daylight: there is sun, but clear skies are not the defining feature of September. Keep outdoor plans movable and bring lightweight rain protection that will not feel too heavy in the humidity. If your holiday depends on consistently dry days, March, February or April are better months to consider overall.

Warm seas are the strongest draw

The sea averages 29.2°C, making swimming a clear reason to consider September. It is warm water rather than a bracing dip, so do not expect the sea to feel sharply cooling after time in the humid air. Pack swimwear alongside your rain protection: the appeal here is warmth despite the wet weather, not warmth without it. From London, the flight takes about 9 h 30 min, so this is a long-haul commitment for a month with a clear weather compromise. It makes most sense if swimming and hot evenings matter more to you than maximising sunshine or keeping every outdoor plan fixed.