Saint-Louis weather in September
September in Saint-Louis: sweltering, a little rain, with muggy air — a gamble, with 39°C afternoons.
Updated September 2026 · climate normals from ERA5 reanalysis
#12 of 12 months in Saint-Louis · #1100 of 1413 destinations to visit in September · comfort 62/100 (tier C)
- Days
- 33°C
- Nights
- 25°C
- Wet days
- 8
- Sun
- 10.6 h
- Humidity
- 78%
- Daylight
- 12 h
Traveller notes on Saint-Louis in September
Saint-Louis's own Tripadvisor forum doesn't have much September-specific weather discussion, so this is grounded in the destination's real climate record rather than a traveler account: this is the tail end of Senegal's rainy season, with hot, humid days in the low 30s C and a real but not overwhelming chance of rain most days. Evenings stay warm too, so it's worth planning riverside walks or boat trips for the cooler morning hours rather than midday. The wet season here is milder than further south in West Africa, so it shouldn't be a dealbreaker for a visit.
Other months in Saint-Louis
Forum posters describe March as sitting within Senegal's dry season along the coast, with daily temperatures generally between 25-32C and low humidity typical for the season - conditions posters describe as comfortable for sightseeing. Posters do flag that some years bring a Harmattan-driven dusty, hazy stretch with a notably brown sky even in March, a real possibility to prepare for even during the otherwise dry, sunny season. Posters note that temperatures and humidity climb noticeably once you head inland away from Saint-Louis' coastal position, so the city itself should stay comparatively milder than destinations further from the Atlantic during the same March visit.
Add your own note from Saint-Louis's card on the map.
Saint-Louis climate normals — September
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Saint-Louis in September
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
BusyMagal of the Two Rakkas, school holidays in 2 of the markets that fill it(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Saint-Louis's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Toughest weatherSaint-Louis's weather peaks January–March.
September coincides with Senegal River flood season.
Best weatherFair weatherToughest weather
What's on in Saint-Louis in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Hazard
Senegal River flood season
15 Jul – 31 Oct · usuallyRain far upstream swells the Senegal River from July to October, and in high years it spills into low-lying mainland neighbourhoods and the northern tip of the island. Local downpours add to it where the drains back up. Source ↗
- Festival
Magal of the Two Rakkas
3–5 Sep · usuallyReligious feastCrowdedEach 5 September Mourides gather in Saint-Louis to commemorate the two prayer units Cheikh Ahmadou Bamba performed in the colonial governor's office in 1895. Thousands of pilgrims fill the island and the streets around the governorate. Source ↗
Where is Saint-Louis?
Saint-Louis in September — FAQ
- Is September a good time to visit Saint-Louis?
- September in Saint-Louis: sweltering, a little rain, with muggy air — a gamble, with 39°C afternoons. It ranks #12 of 12 months for Saint-Louis on SeasonMap's comfort score (62/100).
- What is the weather like in Saint-Louis in September?
- In September, Saint-Louis averages a daily high of 32.8°C and a low of 25.4°C, with about 63.6 mm of rain over roughly 8.2 rainy days.
- What is the air quality in Saint-Louis in September?
- Saint-Louis has a mean US Air Quality Index of about 74 in September.