Climate and average weather in Kalmunai

In Kalmunai, the weather is muggy, hot, wet, and mostly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around December.

Best: late December to early April

Over the course of the year, the temperature in Kalmunai typically varies from 24°C to 32°C, and is rarely below 23°C or above 33°C. June is the hottest month of the year, while January is the coldest.

Based on the travel score, the best time of year to visit Kalmunai for warm-weather activities is from late December to early April.

Hottest
Jun
32°
Coldest
Jan
24°
Wettest
Dec
310 mm
Driest
Jul
31 mm
Rain / yr
1396 mm
171 wet days
Daylight
11.6–12.4 h
shortest–longest
Elevation
10 m
7.4°N
Clearest
Mar
48% cloud

Kalmunai is human settlement.

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

Kalmunai weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late December to early April.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Kalmunai, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

Temperatures in Kalmunai stay fairly even through the year, without a distinct hot or cool season. The warmest month is June, with an average high of 32°C and low of 27°C; the coolest is January, with an average low of 24°C and high of 27°C.

Days typically run about 4°C warmer than nights year-round.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan2724
Feb2824
Mar2925
Apr3026
May3127
Jun3227
Jul3227
Aug3227
Sep3126
Oct2926
Nov2825
Dec2724

How hot and cold Kalmunai really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the hottest afternoons, once humidity is folded in, Kalmunai feels like about 40°C (around May 18). About 233 days a year carry some heat stress, and 26 of them tip into dangerous heat (feels-like above 39°C), peaking in May.

20°25°30°35°40°JanFebMarAprMayJunJulAugSepOctNovDecdangerous heat
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan27272424
Feb30282424
Mar32292525
Apr37302626
May39312727
Jun38322727
Jul37322727
Aug36322727
Sep36312626
Oct34292626
Nov31282525
Dec29272424

Average hourly temperature in Kalmunai

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on June afternoons, near 32°C, and coldest before dawn in January, near 24°C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Kalmunai weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 24°18617.811.65.3
Feb28° / 24°951311.85.8
Mar29° / 25°609.911.95.7
Apr30° / 26°7013.412.24.5
May31° / 27°5911.612.34.0
Jun32° / 27°326.612.44.0
Jul32° / 27°317.612.44.0
Aug32° / 27°429.312.24.1
Sep31° / 26°6713.7124.0
Oct29° / 26°16420.811.83.8
Nov28° / 25°28024.711.73.9
Dec27° / 24°31022.511.64.5

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Kalmunai gets about 1396 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 4.8 months, from around Sep 20 to Feb 12, peaking in November at about 83% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jun 24.

December is the wettest month by volume, with 310 mm over about 23 wet days; July is the driest, with 31 mm.

0%10%20%30%40%50%60%70%80%90%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetNov 20 · 83%Jun 24 · 18%
Rain on a day (%)Rain days
Jan5818
Feb4613
Mar3410
Apr4413
May3712
Jun237
Jul248
Aug319
Sep4514
Oct6721
Nov8225
Dec7323

Monthly rainfall

Over a full year, Kalmunai collects about 1396 mm of rain across 171 wet days — roughly 116 mm in an average month.

It doesn’t fall evenly. December is the wettest month with 310 mm, while July is the driest at just 31 mm. The three wettest months alone bring about 56% of the year’s total.

050100150200250300350JanFebMarAprMayJunJulAugSepOctNovDec1869560705932314267164280310
Rainfall (mm)Rain days
Jan18618
Feb9513
Mar6010
Apr7013
May5912
Jun327
Jul318
Aug429
Sep6714
Oct16421
Nov28025
Dec31023

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Kalmunai, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around December 29 and lasts for 4.5 months, ending around May 15. The clearest month is March, when the sky is clear, mostly clear, or partly cloudy 64% of the time on average.

The cloudier part of the year begins around May 16 and lasts for 7.5 months, ending around December 28. The cloudiest month is July, when it is overcast or mostly cloudy 78% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecMar 21 · 66%Jul 20 · 20%clearmostly clearpartly cloudymostly cloudyovercastclearercloudier
Clearer (%)Cloudier (%)
Jan4357
Feb5545
Mar6436
Apr5050
May3763
Jun2575
Jul2278
Aug2476
Sep3367
Oct3268
Nov2674
Dec3169

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around May 19, brings about 12 h 24 min of light; the shortest, around January 1, only 11 h 36 min — a swing of roughly 0 h 48 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan11.66:246:00
Feb11.86:256:10
Mar11.96:146:11
Apr12.25:586:08
May12.35:496:09
Jun12.45:506:16
Jul12.45:576:20
Aug12.25:596:14
Sep12.05:565:58
Oct11.85:535:43
Nov11.75:585:38
Dec11.66:125:46

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Kalmunai averages about 6 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 3 and 15 days.

The sunnier stretch runs 3.9 months, from around Jan 20 to May 19. The sunniest month is March, with roughly 14 sunny days (mixed).

The greyest month is July, down near 3 sunny days — about 79% fewer than the March peak.

05101520JanFebMarAprMayJunJulAugSepOctNovDecsunniergreyergloomymixedbrightMar 2015 daysJul 163 days
Sunny daysSky
Jan6Gloomy
Feb9Mixed
Mar14Mixed
Apr11Mixed
May7Gloomy
Jun3Gloomy
Jul3Gloomy
Aug3Gloomy
Sep4Gloomy
Oct4Gloomy
Nov4Gloomy
Dec5Gloomy

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

Kalmunai is humid all year round — on a typical day the air feels at least humid, and there is no real dry season to wait for.

The stickiest month is January, when it feels muggy, oppressive or miserable about 98% of the time. Even in January, the mildest month, the air is dry or comfortable only 0% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecmiserableoppressivemuggy
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan227701
Feb225703
Mar0107218
Apr002970
May001090
Jun016039
Jul077815
Aug057817
Sep017425
Oct008020
Nov02899
Dec012843

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Kalmunai is typically calm, near 10 km/h, and varies moderately with the seasons.

The windier part of the year lasts 4.3 months, from around Nov 15 to Mar 25. The windiest month is January, averaging about 14 km/h (light breeze).

The calmer part of the year runs from around Mar 26 to Nov 14, with October the calmest month at about 8 km/h.

05101520JanFebMarAprMayJunJulAugSepOctNovDecwindiercalmerwindiercalmlight breezeJan 9 · 14 km/hOct 12 · 8 km/h
Wind speed (km/h)Feels
Jan14light breeze
Feb12light breeze
Mar10calm
Apr9calm
May8calm
Jun9calm
Jul9calm
Aug8calm
Sep8calm
Oct8calm
Nov10calm
Dec13light breeze

Hazard calendar for Kalmunai

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

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

Kalmunai'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

Best time to visit Kalmunai

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Kalmunai throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around early January, Kalmunai is still near the start of its best-weather window — great conditions with the peak-season crowds not yet at full swing.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Kalmunai for general outdoor tourist activities is from late December to early April, with a peak score in the third week of February.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationFeb 21 · 6.0

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan5.3fair
Feb5.8good
Mar5.6good
Apr4.5fair
May4.0fair
Jun4.0fair
Jul4.0fair
Aug4.1fair
Sep4.1fair
Oct3.8fair
Nov3.9fair
Dec4.5fair

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Kalmunai for hot-weather activities is from early February to mid September, with a peak score in the third week of March.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationMar 20 · 7.3

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Kalmunai, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

Kalmunai packs about the same all year — highs hold near 32°C. Across the year the things worth having are light clothes, sun protection and rain gear.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In June, Kalmunai sees daytime highs around 32°C and nights near 27°C. Pack light clothes. Worth having: sun protection. About 7 days see rain.

Sea temperature near Kalmunai

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea offshore 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 (midday) in Kalmunai by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Kalmunai peaks around April 19 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 21 at about 10 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeApr 19UV 14Dec 21UV 10
UV index (midday)Level
Jan10Extreme
Feb12Extreme
Mar13Extreme
Apr14Extreme
May14Extreme
Jun11Extreme
Jul11Extreme
Aug13Extreme
Sep13Extreme
Oct12Extreme
Nov11Extreme
Dec10Very high

Average hourly UV index in Kalmunai

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in April the burn window is concentrated in the middle of the day: about 8 hours a day reach index 3 (protection recommended), and 6.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan7.55
Feb86
Mar86
Apr86.5
May8.56.5
Jun86
Jul85.5
Aug86
Sep86
Oct86
Nov7.55.5
Dec7.55

Air quality in Kalmunai by month

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.

Air quality in Kalmunai is worst in May — around 25 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateMay 2125 µg/m³Dec 2118 µg/m³
PM2.5 (µg/m³)Level
Jan19Moderate
Feb19Moderate
Mar20Moderate
Apr19Moderate
May25Moderate
Jun23Moderate
Jul23Moderate
Aug23Moderate
Sep22Moderate
Oct22Moderate
Nov20Moderate
Dec18Moderate
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Kalmunai is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecfrost-free year round
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov1000
Dec1000

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Kalmunai banks about 6,462 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around June.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan480
Feb446
Mar527
Apr546
May595
Jun590
Jul604
Aug593
Sep557
Oct543
Nov493
Dec488

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Kalmunai receives about 5.5 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 3.9 and 6.3 kWh/m².

The brighter stretch of the year lasts 7.8 months, from around Feb 17 to Oct 12. The brightest month is March, averaging about 6.2 kWh/m² (intense).

The dimmest month is December, down near 4.0 kWh/m² — roughly 35% less than the March peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmerbrighterdimmerdimmoderatebrightintenseMar 246.3 kWhDec 173.9 kWh
Solar energy (kWh/m²)Level
Jan4.5Bright
Feb5.3Bright
Mar6.2Intense
Apr6.1Intense
May6.0Intense
Jun5.9Bright
Jul5.8Bright
Aug6.0Bright
Sep6.0Bright
Oct5.3Bright
Nov4.3Bright
Dec4.0Bright

Where is Kalmunai?

Kalmunai sits at 7.4°N, 81.8°E, 10 m above sea level, in Sri Lanka. The nearest listed city is Ampara, 21 km away.

BatticaloaEravur TownPottuvilVakaraiBadullaEllaPolonnaruwa

Topography around Kalmunai

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

Within 3 km, the terrain around Kalmunai has only modest variations in elevation — a maximum elevation change of 13 m around an average of 2 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 62 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,357 m.

The land around Kalmunai is covered by water (43%) within 3 km, water (53%) and cropland (30%) within 16 km, and water (43%) and trees (38%) within 80 km.

3 km
13 m
16 km
62 m
80 km
1,357 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetlandmangroves
Nearby: Ampara 21 km · Batticaloa 37 km · Eravur Town 48 km · Pottuvil 59 km · Vakarai 92 km · Badulla 98 km · Ella 105 km · Polonnaruwa 109 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 Kalmunai (7.409°, 81.8347°, elevation 10 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).