Katunayaka weather in September

In September, Katunayaka sees average daytime highs of 29°C and overnight lows near 25°C, with 232 mm of rain across 27.4 wet days and about 12 hours of daylight. It is the 10th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 3% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 h 06 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Katunayaka's 7th-clearest and 4th-windiest month. For the whole year in context, see Katunayaka's year-round climate.

Daytime high
29°
10th warmest
Overnight low
25°
7th coldest
Rainfall
232 mm
27.4 wet days
Daylight
12 hours
6:04 AM – 6:06 PM
Cloud cover
80%
7th clearest
Wind
12 km/h
4th windiest
Solar energy
4.89 kWh/m²
Travel score
3.0
out of 10

Katunayaka is suburb in Western Province.

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 29°C through the month.

A typical September day in Katunayaka reaches about 29°C in the afternoon and slips back to 25°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 30°C. Set against its neighbours, September runs on par with August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12925
22925
32925
42925
52925
62925
72925
82925
92925
102925
112925
122925
132925
142925
152925
162925
172925
182925
192925
202925
212925
222925
232925
242925
252925
262925
272925
282925
292925
302925

How September really feels in Katunayaka

Once humidity and wind are folded in, September averages 30 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
30
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Katunayaka weather by month

How September compares with the rest of the year at a glance. September is the 10th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan31° / 23°486.711.64.9
Feb32° / 24°486.611.84.1
Mar33° / 25°9115123.2
Apr32° / 25°18326.412.22.6
May30° / 26°23428.912.32.6
Jun29° / 26°25328.612.42.8
Jul29° / 25°23028.412.43.0
Aug29° / 25°20928.612.23.0
Sep29° / 25°23227.4123.0
Oct29° / 24°3412811.83.0
Nov30° / 24°29922.711.73.4
Dec30° / 23°14814.311.64.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 3% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 12% of September, with mostly cloudy or overcast conditions the remaining 85%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
11288
21288
31387
41387
51486
61486
71486
81585
91585
101585
111585
121684
131684
141684
151684
161684
171684
181684
191684
201684
211585
221585
231585
241585
251585
261585
271684
281684
291684
301684

Chance of precipitation in September

Any precipitation

Katunayaka gets around 232 mm of rain over 27.4 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 92% and peaks near 94% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
190
290
390
490
590
690
790
890
990
1090
1191
1291
1392
1492
1593
1693
1793
1894
1994
2094
2194
2294
2394
2493
2593
2693
2792
2892
2992
3091

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the miserable band about 76% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
12872
22872
32872
42872
52872
62872
72773
82773
92674
102575
112476
122476
132377
142278
152179
162080
171981
181981
191981
201981
211981
222080
232179
242179
252278
262377
272377
282476
292575
302575

Wind in September

Winds average 12 km/h in September.

Across September, daily wind ranges from about 11 km/h on the calmest days to 12 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
112light breeze
212light breeze
312light breeze
412light breeze
512light breeze
612light breeze
712light breeze
812light breeze
912light breeze
1012light breeze
1112light breeze
1212light breeze
1312light breeze
1412light breeze
1512light breeze
1612calm
1712calm
1812calm
1912calm
2012calm
2112calm
2211calm
2311calm
2411calm
2511calm
2611calm
2711calm
2811calm
2911calm
3011calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 06 min at the start of September to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 12 minutes over September. Sunrise moves from 6:06 AM to 6:01 AM, and sunset from 6:14 PM to 5:58 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.16:066:14
212.16:066:14
312.16:066:13
412.16:066:13
512.16:056:12
612.16:056:12
712.16:056:11
812.16:056:10
912.16:056:10
1012.16:056:09
1112.16:046:09
1212.16:046:08
1312.16:046:08
1412.16:046:07
1512.06:046:07
1612.06:046:06
1712.06:036:05
1812.06:036:05
1912.06:036:04
2012.06:036:04
2112.06:036:03
2212.06:036:03
2312.06:026:02
2412.06:026:01
2512.06:026:01
2612.06:026:00
2712.06:026:00
2812.06:025:59
2912.06:025:59
3011.96:015:58

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.89 kWh/m².

For context, solar energy here swings from a low near 4.49 kWh/m² to a high of 6.27 kWh/m² in March across the year — September's 4.89 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
105.0Bright
114.9Bright
124.9Bright
134.9Bright
144.9Bright
154.9Bright
164.9Bright
174.9Bright
184.9Bright
194.9Bright
204.9Bright
214.9Bright
224.8Bright
234.8Bright
244.8Bright
254.8Bright
264.8Bright
274.8Bright
284.8Bright
294.8Bright
304.8Bright
Planning a trip in September

Hazard calendar for Katunayaka

In seasonPeak

In September, Katunayaka sits inside its cyclone season. The full year is below, with each hazard's peak months called out.

Katunayaka sits in the North Indian Ocean cyclone zone; the season peaks May and October–November.

Cyclone
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Katunayaka?

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

3.0
Sightseeing
6th-best month of the year
4.0
Beach & pool
9th-best month of the year

September is a weaker month for outdoor sightseeing in Katunayaka.

What to pack for Katunayaka in September

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

In September, Katunayaka sees daytime highs around 29°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 27 days see rain.

light clothesrain gearsun protection

Sea temperature near Katunayaka in September

The nearest coast averages about 28°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in April at about 30°C and coldest in August near 27°C.

The water stays above 20°C all year — warm enough for a swim any month.

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Warm
Feb28Tropical
Mar29Tropical
Apr30Tropical
May29Tropical
Jun28Tropical
Jul28Warm
Aug27Warm
Sep28Warm
Oct28Tropical
Nov29Tropical
Dec28Tropical

UV index in Katunayaka in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Katunayaka peaks around February 17 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 15 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highFeb 17UV 13Dec 15UV 10
UV index (midday)Level
Jan11Extreme
Feb13Extreme
Mar12Extreme
Apr12Extreme
May12Extreme
Jun11Extreme
Jul12Extreme
Aug13Extreme
Sep13Extreme
Oct12Extreme
Nov10Extreme
Dec10Very high

Air quality in Katunayaka 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 Katunayaka is worst in November — around 60 µg/m³ PM2.5 (unhealthy), about 2.4× the cleanest month (July, 25 µg/m³).

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

020406080JanFebMarAprMayJunJulAugSepOctNovDecPoorUnhealthyPoorModeratePoorUnhealthyPoorNov 1759 µg/m³Jul 2025 µg/m³
PM2.5 (µg/m³)Level
Jan45Poor
Feb41Poor
Mar57Unhealthy
Apr59Unhealthy
May42Poor
Jun27Moderate
Jul25Moderate
Aug26Moderate
Sep30Moderate
Oct49Poor
Nov60Unhealthy
Dec52Poor
Location & terrain

Where is Katunayaka?

Katunayaka sits at 7.2°N, 79.9°E, 13 m above sea level, in Sri Lanka. The nearest listed city is Negombo, 7.0 km away.

Kelaniya

Topography around Katunayaka

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

Within 3 km, the terrain around Katunayaka has only modest variations in elevation — a maximum elevation change of 36 m around an average of 9 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 70 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,145 m.

The land around Katunayaka is covered by trees (57%) and artificial surfaces (22%) within 3 km, trees (53%) and water (33%) within 16 km, and trees (60%) and water (34%) within 80 km.

3 km
36 m
16 km
70 m
80 km
2,145 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: Negombo 7.0 km · Ja Ela 11 km · Kandana 14 km · Welisara 16 km · Hendala 20 km · Wattala 20 km · Peliyagoda 22 km · Kelaniya 24 km

Sri Lanka travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type D / G / M
230 V · 50 Hz
Prices
≈ 27% of US
price level, 2025
GDP per capita
$5,002
2025
Happiness
4.0 / 10
World Happiness, 2025
Safe drinking water
47%
of population, 2024
Homicide rate
3.3
per 100k, 2019
Road deaths
19.7
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 486
Religion
Buddhist 70%Hindu 13%Muslim 10%Roman Catholic 6%

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 Katunayaka (7.1699°, 79.8884°, elevation 13 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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).