Saint-James, Saint Martin — Weather in September 2026

Climate Overview

Saint-James, Saint Martin in September has hot conditions, with highs reaching 28.5°C (83°F) and afternoons the warmest part of the day. Rain falls on about 17 days this month, totalling around 135 mm. Winds are noticeable. Sea temperature reaches 30°C (86°F).

This month falls at the beginning of Autumn.

Temperatures remain fairly steady throughout September, with daily highs around 28°C (82°F).

September sees fairly even rainfall, totalling about 135 mm across the month.

Expect around 11.1h of sunshine at the start of September, decreasing to 10.5h by the end.

The warmest days tend to fall around the 13th, averaging 28.6°C (83°F).

Compared to August, this month is about 0°C cooler with 3 more rainy days.

Monthly September Averages

Temperature

29°C / 27°C

Feels Like

33°C / 30°C

Rain

17 days · 135 mm

Sunshine

10.7h / day

Humidity

81% — Very Muggy

Wind

27 km/h

Wind Direction

E (93°)

Gusts

37 km/h

Daylight

12.2 h

Cloud Cover

57%

Clear Sky Days

4.8

UV Index

8.5 — Very High

Sea Temperature

30°C

Dew Point

24°C — Oppressive

Moon Phase

Waxing Crescent · 11%

Climate Charts

Daily averages based on historical data (2016–2025)

Daily Temperature

High Low

Daily Precipitation

Rainfall

Daily Sunshine

Sunshine

Daily Wind Speed

Wind Speed

Sun Position

Sunrise 06:00

Daylight 12.2h

Sunset 18:15

What to Expect

Daytime temperatures around 29°C (83°F) are ideal for full-day outdoor exploration. Keep afternoons flexible as tropical showers are common — they typically clear within an hour.

Rain most often builds later in the day, so mornings are typically the driest window and afternoon showers are more likely.

Recent yearly records for September have stayed close to the long-run average.

Compare Months

Month	Temp	Feels Like	Rain	Sun	Humidity	UV	Status	Details
January best	26°C / 25°C	27°C / 25°C	11days (29 mm) Wet	10.4h Excellent	77% Humid	6.7 High	Excellent	View Details
February best	26°C / 24°C	27°C / 24°C	8days (36 mm) Wet	10.7h Excellent	77% Humid	7.6 Very High	Excellent	View Details
March best	26°C / 25°C	28°C / 25°C	8days (22 mm) Wet	11.1h Excellent	76% Humid	8.7 Very High	Excellent	View Details
April best	26°C / 25°C	29°C / 26°C	10days (40 mm) Wet	11.4h Excellent	78% Humid	9 Very High	Excellent	View Details
May	27°C / 26°C	30°C / 27°C	10days (48 mm) Wet	11.7h Excellent	80% Humid	8.8 Very High	Good	View Details
June	28°C / 26°C	31°C / 28°C	10days (43 mm) Wet	11.8h Excellent	80% Humid	8.6 Very High	Good	View Details
July	28°C / 27°C	31°C / 28°C	16days (76 mm) Wet	11.7h Excellent	81% Humid	8.7 Very High	Fair	View Details
August	28°C / 27°C	32°C / 29°C	14days (88 mm) Wet	11.2h Excellent	81% Humid	8.8 Very High	Fair	View Details
September	29°C / 27°C	33°C / 30°C	17days (135 mm) Wet	10.7h Excellent	81% Humid	8.5 Very High	Fair	View Details
October	28°C / 27°C	32°C / 29°C	16days (129 mm) Wet	10.1h Excellent	80% Humid	7.5 Very High	Fair	View Details
November	27°C / 26°C	30°C / 28°C	15days (106 mm) Wet	9.6h Good	80% Humid	6.6 High	Good	View Details
December best	27°C / 25°C	28°C / 26°C	11days (37 mm) Wet	10h Excellent	77% Humid	6.3 High	Excellent	View Details

What to Wear

Summer clothing like shorts, t-shirts, and sundresses will be comfortable. Bring a light cardigan for air-conditioned spaces.

A waterproof jacket or compact umbrella is recommended for occasional showers.

Packing List

UmbrellaWaterproof jacketWaterproof shoesBreathable clothingSunscreen (SPF 30+)Sun hatSunglasses

Frequently Asked Questions

Expand all

Is September a good time to visit Saint-James?

September is typically fair for visiting Saint-James, with average highs of 29°C (83°F) and around 17 rainy days. Saint-James, Saint Martin in September has hot conditions, with highs reaching 28.5°C (83°F) and afternoons the warmest

Does it rain a lot in Saint-James in September?

Saint-James typically sees around 17 rainy days in September with 135 mm (5.3 in) of total rainfall. Pack a waterproof jacket.

Does it get cold at night in Saint-James in September?

Nights stay pleasantly warm in Saint-James during September, around 27°C (80°F). Light evening wear is sufficient.

What should I pack for Saint-James in September?

With highs of 29°C (83°F) and lows of 27°C (80°F) in September, we recommend: Umbrella, Waterproof jacket, Waterproof shoes, Breathable clothing, Sunscreen (SPF 30+). Comfortable walking shoes are essential.

Is September among the best months weather-wise in Saint-James?

September is not the most favourable month weather-wise in Saint-James. Consider visiting during months with milder temperatures or less rainfall for a better experience.

What is the UV index in Saint-James in September?

The average UV index in Saint-James during September is 9 (very high). Strong sun protection is essential — SPF 50+, protective clothing, and avoid prolonged outdoor exposure during peak hours.

How many hours of daylight are there in Saint-James in September?

Saint-James gets approximately 12 hours of daylight per day in September, with around 11 hours of sunshine.

Does it snow in Saint-James in September?

Snow is uncommon in Saint-James during September based on 10-year climate averages.

Last updated: