Chilaw weather in May

In May, Chilaw sees average daytime highs of 30°C and overnight lows near 27°C, with 221 mm of rain across 28.1 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 30°C through the month. The sky is clear or mostly clear about 8% of the time in May, and the air most often feels miserable.

Daylight stretches from about 12 h 18 min at the start of May to 12 h 24 min by month's end. Set against the rest of the year, May is Chilaw's 7th-clearest and 5th-windiest month. For the whole year in context, see Chilaw's year-round climate.

Daytime high
30°
4th warmest
Overnight low
27°
12th coldest
Rainfall
221 mm
28.1 wet days
Daylight
12 h 18 min
5:57 AM – 6:17 PM
Cloud cover
76%
7th clearest
Wind
19 km/h
5th windiest
Solar energy
5.24 kWh/m²
Travel score
3.0
out of 10

Chilaw is large town in Puttalam district, Sri Lanka.

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

Temperature in May

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 30°C through the month.

A typical May day in Chilaw reaches about 30°C in the afternoon and slips back to 27°C overnight — a 3°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, May runs on par with April and about 1°C warmer than June.

25°28°30°33°35°151015202531
Avg high (°C)Avg low (°C)
13027
23027
33027
43027
53027
63027
73027
83027
93027
103027
113027
123027
133027
143027
153027
163027
173027
183027
193027
202927
212927
222927
232927
242927
252927
262927
272927
282927
292927
302927
312927

How May really feels in Chilaw

Once humidity and wind are folded in, May averages 31 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
31
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

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

Chilaw weather by month

How May compares with the rest of the year at a glance. May is the 4th-warmest and 3rd-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 24°376.111.65.7
Feb31° / 25°33611.85.2
Mar31° / 26°6913.711.94.4
Apr30° / 26°15224.912.23.2
May30° / 27°22128.112.33.0
Jun29° / 27°18525.812.43.4
Jul28° / 26°13322.112.44.0
Aug28° / 26°12921.912.24.1
Sep28° / 26°18024.4123.7
Oct29° / 26°29826.111.83.5
Nov29° / 25°26122.211.73.8
Dec29° / 25°13113.511.65.0

Cloud cover in May

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 8% of the time in May.

Beyond those clear spells, partly cloudy skies cover about 19% of May, with mostly cloudy or overcast conditions the remaining 74%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
13565
23466
33367
43367
53268
63268
73169
83169
93070
102971
112971
122971
132872
142773
152674
162773
172674
182575
192575
202476
212476
222278
232278
242278
252179
262179
272080
282080
292080
301981
311981

Chance of precipitation in May

Any precipitation

Chilaw gets around 221 mm of rain over 28.1 wet days in May. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 90% and peaks near 93% on the wettest days.

0%20%40%60%80%100%151015202531
Rain chance (%)
188
288
389
489
589
689
789
889
989
1089
1189
1289
1389
1489
1589
1689
1789
1890
1990
2090
2191
2291
2391
2492
2592
2692
2792
2892
2993
3093
3192

Humidity in May

DryComfortableHumidMuggyOppressiveMiserable

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

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

0%25%50%75%100%151015202531
Oppressive (%)Miserable (%)
1298
2199
3199
4199
5199
6199
7199
8199
9199
10199
110100
120100
130100
140100
150100
160100
170100
180100
190100
200100
210100
220100
230100
240100
250100
260100
270100
28199
29199
30199
31199

Wind in May

Winds average 19 km/h in May.

Across May, daily wind ranges from about 14 km/h on the calmest days to 22 km/h at its breeziest. It stays fairly steady from day to day.

0510152025151015202531
Wind speed (km/h)Feels
114light breeze
215light breeze
315light breeze
415light breeze
516light breeze
616light breeze
716light breeze
817light breeze
917light breeze
1017light breeze
1118light breeze
1218light breeze
1318light breeze
1419light breeze
1519light breeze
1619light breeze
1720light breeze
1820light breeze
1920breezy
2020breezy
2121breezy
2221breezy
2321breezy
2421breezy
2521breezy
2621breezy
2721breezy
2822breezy
2922breezy
3022breezy
3122breezy

Sunrise & sunset in May

DaylightNight

Daylight runs from about 12 h 18 min at the start of May to 12 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over May. Sunrise moves from 6:00 AM to 5:56 AM, and sunset from 6:16 PM to 6:20 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
112.36:006:16
212.36:006:16
312.36:006:16
412.35:596:16
512.35:596:16
612.35:596:16
712.35:586:16
812.35:586:16
912.35:586:16
1012.35:586:17
1112.35:586:17
1212.35:576:17
1312.35:576:17
1412.35:576:17
1512.35:576:17
1612.35:576:17
1712.35:576:18
1812.45:566:18
1912.45:566:18
2012.45:566:18
2112.45:566:18
2212.45:566:18
2312.45:566:19
2412.45:566:19
2512.45:566:19
2612.45:566:19
2712.45:566:19
2812.45:566:20
2912.45:566:20
3012.45:566:20
3112.45:566:20

Solar energy in May

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in May, about 5.24 kWh/m².

For context, solar energy here swings from a low near 4.7 kWh/m² to a high of 6.51 kWh/m² in March across the year — May's 5.24 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.6Bright
25.5Bright
35.5Bright
45.5Bright
55.5Bright
65.4Bright
75.4Bright
85.4Bright
95.4Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.2Bright
185.2Bright
195.2Bright
205.2Bright
215.2Bright
225.2Bright
235.2Bright
245.1Bright
255.1Bright
265.1Bright
275.1Bright
285.1Bright
295.1Bright
305.0Bright
315.0Bright
Planning a trip in May

Hazard calendar for Chilaw

In seasonPeak

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

Chilaw 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 May a good time to visit Chilaw?

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

3.0
Sightseeing
12th-best month of the year
4.1
Beach & pool
12th-best month of the year

May is a weaker month for outdoor sightseeing in Chilaw.

What to pack for Chilaw in May

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

In May, Chilaw sees daytime highs around 30°C and nights near 27°C. Pack light clothes and rain gear. Worth having: sun protection. About 28 days see rain.

light clothesrain gearsun protection

Sea temperature near Chilaw in May

The nearest coast averages about 29°C in May — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 20 km away) 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
Feb28Warm
Mar29Tropical
Apr30Tropical
May29Tropical
Jun28Tropical
Jul27Warm
Aug27Warm
Sep28Warm
Oct28Tropical
Nov29Tropical
Dec28Tropical

UV index in Chilaw in May

LowModerateHighVery highExtreme

Clear-sky midday UV in May 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 Chilaw peaks around April 18 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 19 at about 9 (very high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highApr 18UV 13Dec 19UV 9
UV index (midday)Level
Jan10Very high
Feb13Extreme
Mar13Extreme
Apr13Extreme
May13Extreme
Jun11Extreme
Jul12Extreme
Aug13Extreme
Sep13Extreme
Oct12Extreme
Nov10Extreme
Dec9Very high

Air quality in Chilaw in May

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where May falls, not just the annual average.

Air quality in Chilaw is worst in March — around 30 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (August, 17 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecModerateMar 2030 µg/m³Aug 2417 µg/m³
PM2.5 (µg/m³)Level
Jan23Moderate
Feb23Moderate
Mar30Moderate
Apr28Moderate
May24Moderate
Jun18Moderate
Jul17Moderate
Aug17Moderate
Sep17Moderate
Oct19Moderate
Nov24Moderate
Dec23Moderate
Location & terrain

Where is Chilaw?

Chilaw sits at 7.6°N, 79.8°E, 8 m above sea level, in Sri Lanka. The nearest listed city is Negombo, 41 km away.

NegomboKatunayakaPuttalamJa ElaKandanaWelisaraKurunegalaHendala

Topography around Chilaw

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

Within 3 km, the terrain around Chilaw has only modest variations in elevation — a maximum elevation change of 15 m around an average of 3 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 67 m; within 80 km, large variations in elevation — a maximum elevation change of 977 m.

The land around Chilaw is covered by water (38%) and trees (33%) within 3 km, water (52%) and trees (39%) within 16 km, and trees (53%) and water (37%) within 80 km.

3 km
15 m
16 km
67 m
80 km
977 m
treesgrasslandcroplandartificial surfacesbare terrainwaterwetlandmangroves
May weather nearby: Negombo 41 km · Katunayaka 46 km · Puttalam 51 km · Ja Ela 57 km · Kandana 60 km · Welisara 62 km · Kurunegala 64 km · Hendala 66 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 Chilaw (7.5758°, 79.7953°, elevation 8 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).