Watamu weather in September
September in Watamu: hot, a little rain, with clean air — an excellent time to visit.
Updated September 2026 · climate normals from ERA5 reanalysis
#3 of 12 months in Watamu · #203 of 1413 destinations to visit in September · comfort 91/100 (tier S)
- Days
- 29°C
- Nights
- 24°C
- Wet days
- 11
- Sun
- 11.1 h
- Humidity
- 77%
- Daylight
- 12 h

Traveller notes on Watamu in September
Notes from nearby Mombasa (87 km away)
Watamu doesn't have its own notes for September yet — these are about Mombasa, close enough to share the season.
September here is described as fine weather with the occasional short shower, and notably not as hot as the rest of the year. Our rain figures say exactly that, in a way either number alone would hide: 44.8mm spread across 15.2 days is about three millimetres on each day it rains - frequent, brief, and not a reason to change a plan. Air is 28.7C but reads as 32C at 77.4 percent humidity, and the nights hold 22.6C. The sea is 26.6C. The caveat regulars add is about conditions rather than weather: it is windy now, 18.4 kph, so the water turns choppy and visibility drops - a better month for the beach than for diving. The record: 10.8 hours of sun and AQI 35.
Other months in Watamu
Watamu forum threads describe August as Kenya's cooler 'winter' by local standards, though the coast stays tropical - warm to hot days, cooler but rarely cold evenings, with a short shower possible in the morning or afternoon that usually clears within minutes. The standout theme across threads was wind: August is genuinely one of the windier months here, which forum regulars framed as a plus for kitesurfing and windsurfing but a real consideration for anyone hoping for calm-water snorkeling or diving, which posters said is better served by the October-to-March window instead.
Forum posters describe February as bringing welcome, gentle sea breezes that pick up in the afternoon rather than anything uncomfortably strong, and specifically note seaweed isn't a problem on the beaches this time of year - a real seasonal nuisance in some other months. Posters name the October-to-March stretch overall as the best window for Watamu's beach conditions, with February falling comfortably within that favorable run. The general climate is described as hot and humid with occasional short, intense showers followed quickly by a return to sun and high humidity - a pattern consistent with this being one of the coast's drier, more settled months rather than a washout risk.
Add your own note from Watamu's card on the map.
Watamu climate normals — September
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Watamu 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.
Busyschool holidays in 2 of the markets that fill it, one of its best months for weather(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Watamu'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).
Fair weatherWatamu's weather doesn't swing hard through the year — comfort stays fairly steady in every month.
What's on in Watamu in September
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Nature
Green turtle nesting
1 Apr – 31 Oct · usuallyGreen, hawksbill and olive ridley turtles come up Watamu's beaches to nest through the middle of the year, peaking from April to October. Local Ocean Conservation's night patrols protect the nests, and hatchlings follow roughly two months behind. Source ↗
- Season
Kusi, the windy season
1 Jul – 30 SepWind seasonThe southeast monsoon blows harder and the sea turns choppy, which favours kitesurfers over snorkellers and thins out the marine park's boat traffic. Source ↗
Nearby, and something's on
Within 300 km of Watamu — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Watamu?
Watamu in September — FAQ
- Is September a good time to visit Watamu?
- September in Watamu: hot, a little rain, with clean air — an excellent time to visit. It ranks #3 of 12 months for Watamu on SeasonMap's comfort score (91/100).
- What is the weather like in Watamu in September?
- In September, Watamu averages a daily high of 29.1°C and a low of 23.7°C, with about 34.2 mm of rain over roughly 11 rainy days.
- What is the air quality in Watamu in September?
- Watamu has a mean US Air Quality Index of about 39 in September.
Within 300 km: Lamu's Maulidi around 15 Jul – 30 Sep, and Mombasa's Kusi, the cool monsoon around 15 Jun – 30 Sep.