Unawatuna weather in September

In September, Unawatuna sees average daytime highs of 28°C and overnight lows near 26°C, with 246 mm of rain across 26.5 wet days and about 12 hours of daylight. It is the 11th-warmest and 4th-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 9% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 06 min at the start of September to 12 hours by month's end. Set against the rest of the year, September is Unawatuna's 9th-clearest and 4th-windiest month. For the whole year in context, see Unawatuna's year-round climate.

Daytime high
28°
11th warmest
Overnight low
26°
7th coldest
Rainfall
246 mm
26.5 wet days
Daylight
12 hours
6:02 AM – 6:04 PM
Cloud cover
77%
9th clearest
Wind
19 km/h
4th windiest
Solar energy
5.46 kWh/m²
Travel score
3.8
out of 10

Unawatuna is human settlement.

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 28°C through the month.

A typical September day in Unawatuna reaches about 28°C in the afternoon and slips back to 26°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 28°C. Set against its neighbours, September runs on par with August and on par with October.

20°23°25°28°30°151015202530
Avg high (°C)Avg low (°C)
12726
22726
32726
42726
52726
62726
72826
82826
92826
102826
112826
122826
132826
142826
152826
162826
172826
182826
192826
202826
212826
222826
232826
242826
252826
262826
272826
282826
292826
302826

How September really feels in Unawatuna

Once humidity and wind are folded in, September averages 0 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
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Unawatuna weather by month

How September compares with the rest of the year at a glance. September is the 11th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan28° / 25°6312.111.76.0
Feb28° / 25°5410.711.85.6
Mar29° / 26°6714.2125.1
Apr29° / 26°15323.112.13.8
May29° / 26°27528.312.33.3
Jun28° / 26°24427.412.33.5
Jul28° / 26°20627.312.33.8
Aug27° / 26°20527.312.23.8
Sep28° / 26°24626.5123.8
Oct28° / 26°26126.411.93.9
Nov28° / 25°25323.111.74.2
Dec28° / 25°14718.611.75.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 9% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 15% of September, with mostly cloudy or overcast conditions the remaining 77%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12278
22278
32377
42377
52377
62476
72476
82476
92575
102476
112575
122575
132575
142575
152575
162476
172476
182476
192476
202377
212377
222377
232278
242278
252278
262377
272377
282476
292575
302575

Chance of precipitation in September

Any precipitation

Unawatuna gets around 246 mm of rain over 26.5 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 88% and peaks near 89% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
188
288
389
489
589
689
789
889
989
1089
1189
1289
1389
1489
1589
1689
1789
1888
1988
2088
2188
2288
2387
2487
2586
2686
2786
2885
2985
3085

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 56% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
15644
25644
35743
45743
55743
65743
75743
85743
95743
105644
115644
125545
135545
145446
155446
165347
175347
185446
195446
205446
215545
225545
235545
245644
255743
265743
275842
285842
295941
305941

Wind in September

Winds average 19 km/h in September.

Across September, daily wind ranges from about 18 km/h on the calmest days to 20 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202530
Wind speed (km/h)Feels
120breezy
220breezy
320breezy
420breezy
520breezy
620breezy
720light breeze
820light breeze
920light breeze
1020light breeze
1120light breeze
1220light breeze
1320light breeze
1420light breeze
1520light breeze
1620light breeze
1720light breeze
1820light breeze
1920light breeze
2019light breeze
2119light breeze
2219light breeze
2319light breeze
2419light breeze
2519light breeze
2619light breeze
2719light breeze
2819light breeze
2918light breeze
3018light breeze

Sunrise & sunset in September

DaylightNight

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

Days shrink by about 6 minutes over September. Sunrise moves from 6:05 AM to 6:00 AM, and sunset from 6:12 PM to 5:57 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.16:056:12
212.16:056:12
312.16:056:11
412.16:056:11
512.16:056:10
612.16:046:10
712.16:046:09
812.16:046:09
912.16:046:08
1012.16:046:08
1112.16:036:07
1212.16:036:06
1312.06:036:06
1412.06:036:05
1512.06:036:05
1612.06:026:04
1712.06:026:04
1812.06:026:03
1912.06:026:03
2012.06:026:02
2112.06:016:02
2212.06:016:01
2312.06:016:01
2412.06:016:00
2512.06:015:59
2612.06:005:59
2712.06:005:58
2812.06:005:58
2912.06:005:57
3012.06:005:57

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.46 kWh/m².

For context, solar energy here swings from a low near 4.82 kWh/m² to a high of 6.43 kWh/m² in March across the year — September's 5.46 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.5Bright
25.5Bright
35.5Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.5Bright
115.5Bright
125.5Bright
135.5Bright
145.5Bright
155.5Bright
165.5Bright
175.5Bright
185.5Bright
195.5Bright
205.4Bright
215.4Bright
225.4Bright
235.4Bright
245.4Bright
255.4Bright
265.4Bright
275.4Bright
285.4Bright
295.4Bright
305.4Bright
Planning a trip in September

Hazard calendar for Unawatuna

In seasonPeak

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

Unawatuna 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 Unawatuna?

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

3.8
Sightseeing
7th-best month of the year
4.0
Beach & pool
9th-best month of the year

September is a weaker month for outdoor sightseeing in Unawatuna.

What to pack for Unawatuna in September

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

In September, Unawatuna sees daytime highs around 28°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 27 days see rain.

light clothesrain gearsun protection

Sea temperature near Unawatuna 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 at the nearest coast (about 18 km away) is warmest in April at about 30°C and coldest in July near 28°C.

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

26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan28Warm
Feb28Tropical
Mar29Tropical
Apr30Tropical
May29Tropical
Jun28Tropical
Jul28Warm
Aug28Warm
Sep28Warm
Oct28Tropical
Nov29Tropical
Dec28Tropical

UV index in Unawatuna 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 Unawatuna peaks around April 17 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 11 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeApr 17UV 14Jan 11UV 9
UV index (midday)Level
Jan9Very high
Feb14Extreme
Mar12Extreme
Apr14Extreme
May13Extreme
Jun11Extreme
Jul11Extreme
Aug13Extreme
Sep13Extreme
Oct13Extreme
Nov11Extreme
Dec10Very high

Air quality in Unawatuna 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 Unawatuna is worst in January — around 35 µg/m³ PM2.5 (moderate), about 2.1× the cleanest month (September, 16 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateJan 1834 µg/m³Sep 1316 µg/m³
PM2.5 (µg/m³)Level
Jan35Moderate
Feb31Moderate
Mar25Moderate
Apr21Moderate
May20Moderate
Jun18Moderate
Jul17Moderate
Aug17Moderate
Sep16Moderate
Oct18Moderate
Nov25Moderate
Dec30Moderate
Location & terrain

Where is Unawatuna?

Unawatuna sits at 6.0°N, 80.3°E, 0 m above sea level, in Sri Lanka. The nearest listed city is Galle, 5.0 km away.

MirissaAmbalangodaMataraDevinuwaraBentotaBeliatta

Topography around Unawatuna

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

Within 3 km, the terrain around Unawatuna has only modest variations in elevation — a maximum elevation change of 75 m around an average of 10 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 226 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,357 m.

The land around Unawatuna is covered by trees (53%) and water (34%) within 3 km, water (51%) and trees (45%) within 16 km, and trees (51%) and water (46%) within 80 km.

3 km
75 m
16 km
226 m
80 km
1,357 m
treesgrasslandcroplandartificial surfaceswatermangroves
September weather nearby: Galle 5.0 km · Weligama 20 km · Mirissa 24 km · Ambalangoda 32 km · Matara 33 km · Devinuwara 39 km · Bentota 53 km · Beliatta 53 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 Unawatuna (6.0212°, 80.2503°, elevation 0 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).