Siaya weather in September

In September, Siaya sees average daytime highs of 27°C and overnight lows near 19°C, with 134 mm of rain across 24.4 wet days and about 12 hours of daylight. It is the 4th-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 27°C through the month. The sky is clear or mostly clear about 20% of the time in September, and the air most often feels humid.

Daylight stretches from about 12 hours at the start of September to 12 hours by month's end. Set against the rest of the year, September is Siaya's 3rd-clearest and 4th-windiest month. For the whole year in context, see Siaya's year-round climate.

Daytime high
27°
4th warmest
Overnight low
19°
6th coldest
Rainfall
134 mm
24.4 wet days
Daylight
12 hours
6:37 AM – 6:37 PM
Cloud cover
62%
3rd clearest
Wind
7 km/h
4th windiest
Solar energy
6.4 kWh/m²
Travel score
4.3
out of 10

Siaya is town in Siaya County, Kenya.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 27°C through the month.

A typical September day in Siaya reaches about 27°C in the afternoon and slips back to 19°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 28°C. Set against its neighbours, September runs on par with August and on par with October.

15°20°25°30°151015202530
Avg high (°C)Avg low (°C)
12719
22719
32719
42719
52719
62719
72719
82719
92719
102719
112719
122719
132719
142719
152719
162719
172719
182719
192719
202719
212719
222720
232720
242720
252720
262720
272720
282720
292720
302720

Siaya weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 20°13718.3125.3
Feb28° / 20°10715.2125.1
Mar27° / 20°19822.8124.6
Apr26° / 20°28027.5123.7
May26° / 20°23128.4123.9
Jun26° / 19°12923.4124.5
Jul26° / 19°9919.9125.1
Aug26° / 19°12422.6124.8
Sep27° / 19°13424.4124.3
Oct27° / 20°21228.1123.8
Nov26° / 19°23227.3123.8
Dec27° / 19°18323.1124.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 20% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 27% of September, with mostly cloudy or overcast conditions the remaining 52%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14951
24951
34951
45050
55050
65149
75248
85149
95248
105248
115347
125347
135347
145347
155248
165248
175149
185050
194951
204852
214852
224654
234456
244357
254258
264159
273961
283961
293862
303763

Chance of precipitation in September

Any precipitation

Siaya gets around 134 mm of rain over 24.4 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 82% and peaks near 88% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%80%100%151015202530
Rain chance (%)
178
278
378
478
579
679
779
879
979
1080
1180
1280
1380
1480
1580
1681
1781
1881
1981
2082
2182
2283
2384
2484
2585
2686
2786
2887
2987
3088

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels humid — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the humid band about 74% of days. Sticky, muggy-or-worse air turns up on roughly 25% of them.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)
12899
228810
328711
428612
528513
628414
728315
828216
918118
1018019
1117920
1217821
1317623
1417524
1517425
1617326
1717227
1817128
1917029
2016930
2116831
2216732
2316633
2416435
2516336
2616237
2716039
2815940
2915841
3005743

Wind in September

Winds average 7 km/h in September.

Across September, daily wind ranges from about 6 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 hours at the start of September to 12 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 0 minutes over September. Sunrise moves from 6:43 AM to 6:32 AM, and sunset from 6:43 PM to 6:32 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.06:436:43
212.06:426:42
312.06:426:42
412.06:426:42
512.06:416:41
612.06:416:41
712.06:406:41
812.06:406:40
912.06:406:40
1012.06:396:39
1112.06:396:39
1212.06:396:39
1312.06:386:38
1412.06:386:38
1512.06:386:38
1612.06:376:37
1712.06:376:37
1812.06:366:36
1912.06:366:36
2012.06:366:36
2112.06:356:35
2212.06:356:35
2312.06:356:35
2412.06:346:34
2512.06:346:34
2612.06:346:34
2712.06:336:33
2812.06:336:33
2912.06:336:32
3012.06:326:32

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 6.4 kWh/m².

For context, solar energy here swings from a low near 5.49 kWh/m² to a high of 6.74 kWh/m² in February across the year — September's 6.4 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
16.1Intense
26.1Intense
36.2Intense
46.2Intense
56.2Intense
66.2Intense
76.3Intense
86.3Intense
96.3Intense
106.3Intense
116.3Intense
126.4Intense
136.4Intense
146.4Intense
156.4Intense
166.5Intense
176.5Intense
186.5Intense
196.5Intense
206.5Intense
216.5Intense
226.5Intense
236.5Intense
246.5Intense
256.5Intense
266.5Intense
276.5Intense
286.4Intense
296.4Intense
306.4Intense
Planning a trip in September

Is September a good time to visit Siaya?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

4.3
Sightseeing
8th-best month of the year
4.4
Beach & pool
8th-best month of the year

September is a reasonable time to visit Siaya for sightseeing.

What to pack for Siaya in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Siaya sees daytime highs around 27°C and nights near 19°C. Pack rain gear and sun protection. Worth having: light clothes. About 24 days see rain.

rain gearsun protectionlight clothes

UV index in Siaya in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 12 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Siaya peaks around March 16 at about 16 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 18 at about 10 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeExtremeMar 16UV 16Jun 18UV 10
UV index (midday)Level
Jan15Extreme
Feb14Extreme
Mar16Extreme
Apr14Extreme
May11Extreme
Jun10Very high
Jul11Extreme
Aug11Extreme
Sep12Extreme
Oct14Extreme
Nov12Extreme
Dec11Extreme

Air quality in Siaya in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Siaya is worst in June — around 78 µg/m³ PM2.5 (unhealthy), and holds fairly steady the rest of the year.

Modeled monthly averages (CAMS reanalysis, 2015–2024).

020406080JanFebMarAprMayJunJulAugSepOctNovDecUnhealthyJun 2177 µg/m³Apr 967 µg/m³
PM2.5 (µg/m³)Level
Jan74Unhealthy
Feb68Unhealthy
Mar67Unhealthy
Apr67Unhealthy
May69Unhealthy
Jun78Unhealthy
Jul76Unhealthy
Aug74Unhealthy
Sep71Unhealthy
Oct73Unhealthy
Nov77Unhealthy
Dec76Unhealthy
Location & terrain

Where is Siaya?

Siaya sits at 0.1°N, 34.3°E, 1,321 m above sea level, in Kenya. The nearest listed city is Bondo, 18 km away.

Topography around Siaya

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Siaya.

Within 3 km, the terrain around Siaya has only modest variations in elevation — a maximum elevation change of 156 m around an average of 1,292 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 310 m; within 80 km, large variations in elevation — a maximum elevation change of 1,175 m.

The land around Siaya is covered by shrubs (37%) and grassland (29%) within 3 km, shrubs (42%) and grassland (35%) within 16 km, and water (29%) and shrubs (27%) within 80 km.

3 km
156 m
16 km
310 m
80 km
1,175 m
treesshrubsgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Bondo 18 km · Khwisero 36 km · Lugulu 37 km · Mumias 38 km · Mbale 48 km · Busia 49 km · Busia 50 km · Kisumu 56 km

Kenya travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type G
240 V · 50 Hz
Prices
≈ 34% of US
price level, 2025
GDP per capita
$2,363
2025
Happiness
4.7 / 10
World Happiness, 2025
Homicide rate
4.9
per 100k, 2022
Road deaths
28.3
per 100k/yr, 2019
Income group
Lower middle
World Bank
English
High
EF EPI 593
Religion
Christian 86%Muslim 11%other 2%none 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Siaya (0.0607°, 34.2881°, elevation 1,321 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).