Polonnaruwa weather in September

In September, Polonnaruwa sees average daytime highs of 35°C and overnight lows near 26°C, with 53 mm of rain across 8.2 wet days and about 12 hours of daylight. It is the 1st-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 35°C through the month. The sky is clear or mostly clear about 12% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 12 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Polonnaruwa's 6th-clearest and 4th-windiest month. For the whole year in context, see Polonnaruwa's year-round climate.

Daytime high
35°
1st warmest
Overnight low
26°
8th coldest
Rainfall
53 mm
8.2 wet days
Daylight
12 hours
5:59 AM – 6:02 PM
Cloud cover
73%
6th clearest
Wind
16 km/h
4th windiest
Solar energy
5.93 kWh/m²
Travel score
2.6
out of 10

Polonnaruwa is town in North Central Province, Sri Lanka.

Founded
1070

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 35°C through the month.

A typical September day in Polonnaruwa reaches about 35°C in the afternoon and slips back to 26°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 32°C and 37°C. Set against its neighbours, September runs on par with August and about 2°C warmer than October.

20°25°30°35°40°151015202530
Avg high (°C)Avg low (°C)
13526
23526
33526
43526
53526
63526
73526
83526
93526
103526
113526
123526
133526
143526
153526
163526
173526
183526
193526
203526
213526
223526
233526
243526
253526
263525
273525
283525
293525
303425

How September really feels in Polonnaruwa

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
15 feel dangerously hot (≥ 39°C)
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.

Polonnaruwa weather by month

How September compares with the rest of the year at a glance. September is the 1st-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 22°11014.311.64.8
Feb30° / 22°7310.711.74.7
Mar33° / 23°509.111.93.8
Apr34° / 25°9214.212.22.5
May35° / 26°679.312.42.5
Jun35° / 27°184.112.52.8
Jul35° / 26°265.412.42.8
Aug35° / 26°325.612.32.7
Sep35° / 26°538.2122.6
Oct33° / 25°18117.311.82.7
Nov30° / 23°23322.611.63.2
Dec29° / 23°20719.711.54.1

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 12% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 71%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
12476
22476
32476
42575
52674
62674
72674
82773
92773
102872
112971
123070
133070
143169
153169
163268
173268
183268
193268
203169
213169
223169
233169
243169
253169
263169
273070
283070
293070
303169

Chance of precipitation in September

Any precipitation

Polonnaruwa gets around 53 mm of rain over 8.2 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 27% and peaks near 40% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%50%151015202530
Rain chance (%)
121
222
322
422
522
623
723
823
922
1022
1122
1222
1322
1422
1523
1623
1724
1825
1926
2028
2129
2231
2332
2434
2535
2636
2738
2839
2939
3040

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 70% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
131672
231672
332662
432662
532662
632662
731672
831672
931672
1030682
1130682
1230691
1329701
1428711
1528711
1627721
1727721
1826731
1926722
2025732
2125732
2224742
2324733
2423743
2523734
2623734
2722735
2822735
2922726
3022726

Wind in September

Winds average 16 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 18 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
118light breeze
218light breeze
318light breeze
417light breeze
517light breeze
617light breeze
717light breeze
817light breeze
917light breeze
1017light breeze
1117light breeze
1217light breeze
1317light breeze
1417light breeze
1517light breeze
1617light breeze
1717light breeze
1817light breeze
1917light breeze
2016light breeze
2116light breeze
2216light breeze
2316light breeze
2415light breeze
2515light breeze
2615light breeze
2715light breeze
2814light breeze
2914light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 12 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 18 minutes over September. Sunrise moves from 6:01 AM to 5:57 AM, and sunset from 6:10 PM to 5:53 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.26:016:10
212.16:016:10
312.16:016:09
412.16:016:09
512.16:016:08
612.16:006:07
712.16:006:07
812.16:006:06
912.16:006:06
1012.16:006:05
1112.16:006:05
1212.16:006:04
1312.15:596:03
1412.15:596:03
1512.15:596:02
1612.05:596:02
1712.05:596:01
1812.05:596:00
1912.05:596:00
2012.05:585:59
2112.05:585:59
2212.05:585:58
2312.05:585:57
2412.05:585:57
2512.05:585:56
2612.05:585:56
2712.05:575:55
2812.05:575:55
2911.95:575:54
3011.95:575:53

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.93 kWh/m².

For context, solar energy here swings from a low near 3.83 kWh/m² to a high of 6.3 kWh/m² in March across the year — September's 5.93 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.0Bright
26.0Bright
36.0Bright
46.0Bright
56.0Bright
66.0Bright
76.0Bright
86.0Bright
96.0Bright
106.0Bright
116.0Bright
126.0Bright
136.0Bright
146.0Bright
156.0Bright
166.0Bright
176.0Bright
186.0Bright
196.0Bright
205.9Bright
215.9Bright
225.9Bright
235.9Bright
245.9Bright
255.9Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
Planning a trip in September

Hazard calendar for Polonnaruwa

In seasonPeak

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

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

Polonnaruwa's monsoon runs October–January, when most of the year's rain falls.

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

Is September a good time to visit Polonnaruwa?

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

2.6
Sightseeing
10th-best month of the year
5.5
Beach & pool
7th-best month of the year

September is a weaker month for outdoor sightseeing in Polonnaruwa.

What to pack for Polonnaruwa in September

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

In September, Polonnaruwa sees daytime highs around 35°C and nights near 26°C. Pack light clothes. Worth having: rain gear and sun protection. About 8 days see rain.

light clothesrain gearsun protection

Sea temperature near Polonnaruwa in September

The nearest coast averages about 29°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 63 km away) is warmest in May at about 30°C and coldest in January 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
Jan27Warm
Feb28Warm
Mar29Tropical
Apr30Tropical
May30Tropical
Jun30Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov29Tropical
Dec28Warm

UV index in Polonnaruwa 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 Polonnaruwa peaks around April 20 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 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 highApr 20UV 14Dec 19UV 10
UV index (midday)Level
Jan10Extreme
Feb12Extreme
Mar13Extreme
Apr14Extreme
May14Extreme
Jun11Extreme
Jul11Extreme
Aug12Extreme
Sep13Extreme
Oct12Extreme
Nov11Extreme
Dec10Very high

Air quality in Polonnaruwa 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 Polonnaruwa is worst in May — around 28 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMay 1028 µg/m³Jul 2120 µg/m³
PM2.5 (µg/m³)Level
Jan22Moderate
Feb21Moderate
Mar24Moderate
Apr27Moderate
May28Moderate
Jun21Moderate
Jul20Moderate
Aug20Moderate
Sep21Moderate
Oct25Moderate
Nov24Moderate
Dec22Moderate
Location & terrain

Where is Polonnaruwa?

Polonnaruwa sits at 7.9°N, 81.0°E, 0 m above sea level, in Sri Lanka. The nearest listed city is Sigiriya, 28 km away.

SigiriyaDambullaVakaraiMataleEravur TownTrincomaleeAnuradhapuraBatticaloa

Topography around Polonnaruwa

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

Within 3 km, the terrain around Polonnaruwa has only modest variations in elevation — a maximum elevation change of 38 m around an average of 57 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 297 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,871 m.

The land around Polonnaruwa is covered by trees (48%) and cropland (20%) within 3 km, trees (58%) and cropland (29%) within 16 km, and trees (60%) within 80 km.

3 km
38 m
16 km
297 m
80 km
1,871 m
treesgrasslandcroplandartificial surfaceswater
September weather nearby: Sigiriya 28 km · Dambulla 40 km · Vakarai 52 km · Matale 67 km · Eravur Town 69 km · Trincomalee 75 km · Anuradhapura 77 km · Batticaloa 80 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 Polonnaruwa (7.9397°, 81.0027°, 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).