Jaffna weather in September

In September, Jaffna sees average daytime highs of 29°C and overnight lows near 27°C, with 67 mm of rain across 12 wet days and about 12.1 hours of daylight. It is the 6th-warmest and 4th-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 20% of the time in September, and the air most often feels miserable.

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 Jaffna's 7th-clearest and 5th-windiest month. For the whole year in context, see Jaffna's year-round climate.

Daytime high
29°
6th warmest
Overnight low
27°
7th coldest
Rainfall
67 mm
12 wet days
Daylight
12 h 06 min
6:03 AM – 6:06 PM
Cloud cover
70%
7th clearest
Wind
25 km/h
5th windiest
Solar energy
5.9 kWh/m²
Travel score
4.9
out of 10

Jaffna is capital city of the Northern Province of Sri Lanka.

Density
8,371/km²
people per km²
Founded
1621

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 Jaffna reaches about 29°C in the afternoon and slips back to 27°C overnight — a 2°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 30°C. Set against its neighbours, September runs on par with August and on par with October.

25°28°30°33°35°151015202530
Avg high (°C)Avg low (°C)
12927
22927
32927
42927
52927
62927
72927
82927
92927
102927
112927
122927
132927
142927
152927
162927
172927
182927
192927
202927
212927
222927
232927
242927
252927
262927
272927
282927
292927
302927

How September really feels in Jaffna

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.

Jaffna weather by month

How September compares with the rest of the year at a glance. September is the 6th-warmest and 4th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 25°626.711.57.0
Feb28° / 25°254.211.77.4
Mar29° / 26°223.411.96.5
Apr30° / 28°457.712.25.2
May30° / 28°587.612.45.0
Jun30° / 28°275.512.65.2
Jul30° / 28°339.212.54.9
Aug29° / 28°4810.512.35.0
Sep29° / 27°671212.14.9
Oct29° / 27°20820.911.84.2
Nov28° / 26°3132211.64.5
Dec27° / 25°20016.311.45.5

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 15% of September, with mostly cloudy or overcast conditions the remaining 66%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13070
23070
33070
43070
53169
63169
73169
83268
93268
103268
113367
123367
133466
143466
153565
163664
173763
183763
193763
203763
213763
223664
233664
243763
253763
263664
273664
283763
293763
303862

Chance of precipitation in September

Any precipitation

Jaffna gets around 67 mm of rain over 12 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 40% and peaks near 51% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
135
236
336
436
537
637
738
838
938
1038
1138
1238
1338
1438
1537
1637
1737
1837
1938
2039
2139
2240
2341
2443
2544
2645
2747
2848
2949
3051

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 92% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
1595
2694
3694
4694
5694
6694
7694
8694
9694
10694
11694
12694
13595
14595
15595
16595
17595
18595
19694
20694
21793
22892
23991
241090
251189
261288
271387
281486
291585
301684

Wind in September

Winds average 25 km/h in September.

Across September, daily wind ranges from about 22 km/h on the calmest days to 26 km/h at its breeziest. It stays fairly steady from day to day.

0102030151015202530
Wind speed (km/h)Feels
126breezy
226breezy
326breezy
426breezy
526breezy
626breezy
726breezy
826breezy
926breezy
1026breezy
1126breezy
1226breezy
1326breezy
1426breezy
1526breezy
1626breezy
1726breezy
1826breezy
1925breezy
2025breezy
2125breezy
2225breezy
2324breezy
2424breezy
2524breezy
2623breezy
2723breezy
2823breezy
2922breezy
3022breezy

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 6:04 AM to 6:02 AM, and sunset from 6:15 PM to 5:57 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.26:046:15
212.26:046:15
312.26:046:14
412.26:046:13
512.26:046:13
612.16:046:12
712.16:046:12
812.16:036:11
912.16:036:10
1012.16:036:10
1112.16:036:09
1212.16:036:08
1312.16:036:08
1412.16:036:07
1512.16:036:07
1612.16:036:06
1712.06:036:05
1812.06:036:05
1912.06:026:04
2012.06:026:03
2112.06:026:03
2212.06:026:02
2312.06:026:01
2412.06:026:01
2512.06:026:00
2612.06:025:59
2712.06:025:59
2811.96:025:58
2911.96:025:58
3011.96:025:57

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.9 kWh/m².

For context, solar energy here swings from a low near 4.22 kWh/m² to a high of 6.58 kWh/m² in March across the year — September's 5.9 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.9Bright
25.9Bright
35.9Bright
45.9Bright
55.9Bright
65.9Bright
76.0Bright
86.0Bright
96.0Bright
106.0Bright
116.0Bright
126.0Bright
136.0Bright
146.0Bright
156.0Bright
166.0Bright
176.0Bright
186.0Bright
195.9Bright
205.9Bright
215.9Bright
225.9Bright
235.8Bright
245.8Bright
255.8Bright
265.8Bright
275.7Bright
285.7Bright
295.7Bright
305.7Bright
Planning a trip in September

Hazard calendar for Jaffna

In seasonPeak

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

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

Jaffna's monsoon runs October–December, 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 Jaffna?

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

4.9
Sightseeing
9th-best month of the year
6.4
Beach & pool
9th-best month of the year

September is a reasonable time to visit Jaffna for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Jaffna in September

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

In September, Jaffna sees daytime highs around 29°C and nights near 27°C. Pack light clothes. Worth having: rain gear, sun protection and a windbreaker. About 12 days see rain.

light clothesrain gearsun protectiona windbreaker

Sea temperature near Jaffna 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 14 km away) is warmest in April 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
Feb27Warm
Mar29Tropical
Apr30Tropical
May30Tropical
Jun29Tropical
Jul29Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov28Tropical
Dec27Warm

UV index in Jaffna 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 Jaffna peaks around August 17 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near January 11 at about 8 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highAug 17UV 13Jan 11UV 8
UV index (midday)Level
Jan8Very high
Feb12Extreme
Mar12Extreme
Apr13Extreme
May13Extreme
Jun11Extreme
Jul12Extreme
Aug14Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec9Very high

Air quality in Jaffna 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 Jaffna is worst in May — around 24 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMay 1623 µg/m³Sep 1817 µg/m³
PM2.5 (µg/m³)Level
Jan20Moderate
Feb19Moderate
Mar20Moderate
Apr20Moderate
May24Moderate
Jun19Moderate
Jul18Moderate
Aug19Moderate
Sep17Moderate
Oct18Moderate
Nov17Moderate
Dec19Moderate
Location & terrain

Where is Jaffna?

Jaffna sits at 9.7°N, 80.0°E, 7 m above sea level, in Sri Lanka. The nearest listed city is Valvedditturai, 24 km away.

ValvedditturaiPoint PedroMannarMullaittivuVavuniyaAnuradhapuraTrincomaleePuttalam

Topography around Jaffna

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

Within 3 km, the terrain around Jaffna has only modest variations in elevation — a maximum elevation change of 16 m around an average of 4 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 22 m; within 80 km, only modest variations in elevation — a maximum elevation change of 99 m.

The land around Jaffna is covered by water (45%), trees (26%) and artificial surfaces (22%) within 3 km, water (46%) and trees (24%) within 16 km, and water (77%) within 80 km.

3 km
16 m
16 km
22 m
80 km
99 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetlandmangroves
September weather nearby: Valvedditturai 24 km · Point Pedro 30 km · Mannar 77 km · Mullaittivu 99 km · Vavuniya 115 km · Anuradhapura 157 km · Trincomalee 181 km · Puttalam 183 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 Jaffna (9.6684°, 80.0074°, elevation 7 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).