Mirissa weather in January

In January, Mirissa sees average daytime highs of 29°C and overnight lows near 24°C, with 99 mm of rain across 14.6 wet days and about 11.7 hours of daylight. It is the 4th-warmest and 11th-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 21% of the time in January, and the air most often feels oppressive.

Daylight stretches from about 11 h 42 min at the start of January to 11 h 42 min by month's end. Set against the rest of the year, January is Mirissa's 3rd-clearest and 12th-windiest month. For the whole year in context, see Mirissa's year-round climate.

Daytime high
29°
4th warmest
Overnight low
24°
1st coldest
Rainfall
99 mm
14.6 wet days
Daylight
11 h 42 min
6:27 AM – 6:08 PM
Cloud cover
65%
3rd clearest
Wind
7 km/h
12th windiest
Solar energy
5.53 kWh/m²
Travel score
4.7
out of 10

Mirissa is place in Southern Province, Sri Lanka.

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

Temperature in January

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 29°C through the month.

A typical January day in Mirissa reaches about 29°C in the afternoon and slips back to 24°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 31°C. Set against its neighbours, January runs on par with December and about 1°C cooler than February.

20°25°30°35°151015202531
Avg high (°C)Avg low (°C)
12924
22924
32924
42924
52924
62924
72924
82924
92924
102924
112924
122924
132924
142923
152923
162923
172923
182923
192923
203023
213023
223023
233023
243023
253024
263024
273024
283024
293024
303024
313024

How January really feels in Mirissa

Once humidity and wind are folded in, January 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 January is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Mirissa weather by month

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

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 24°9914.611.74.7
Feb30° / 24°8413.111.84.4
Mar31° / 25°10318.7123.8
Apr30° / 25°18925.712.13.1
May29° / 26°22128.112.33.0
Jun29° / 25°18726.812.33.2
Jul28° / 25°15326.512.33.5
Aug28° / 25°15826.812.23.5
Sep29° / 25°20226.3123.4
Oct29° / 24°25126.511.93.4
Nov29° / 24°29825.111.73.4
Dec29° / 24°20021.411.74.0

Cloud cover in January

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 21% of the time in January.

Beyond those clear spells, partly cloudy skies cover about 20% of January, with mostly cloudy or overcast conditions the remaining 58%.

0%25%50%75%100%151015202531
Clearer (%)Cloudier (%)
14060
24060
34159
44159
54060
64159
74159
84159
94159
104258
114258
124357
134357
144357
154357
164258
174258
184258
194258
204159
214159
224159
234159
244159
254159
264159
274060
284159
294159
304060
314060

Chance of precipitation in January

Any precipitation

Mirissa gets around 99 mm of rain over 14.6 wet days in January. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 46% and peaks near 51% on the wettest days.

0%20%40%60%151015202531
Rain chance (%)
151
251
351
451
551
651
751
851
950
1050
1149
1248
1347
1446
1545
1644
1744
1843
1942
2042
2142
2242
2342
2442
2543
2643
2744
2845
2946
3046
3147

Humidity in January

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, January lands in the oppressive band about 86% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202531
Muggy (%)Oppressive (%)Miserable (%)
18884
28884
38893
48893
58893
68893
79892
89892
99892
1010882
1110882
1211872
1311872
1412862
1512862
1613852
1713852
1814842
1914842
2014842
2114842
2214842
2314842
2414842
2513852
2613852
2713852
2812862
2912862
3012862
3112862

Wind in January

Winds average 7 km/h in January, the calmest month.

Across January, daily wind ranges from about 7 km/h on the calmest days to 8 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202531
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
288calm
298calm
308calm
318calm

Sunrise & sunset in January

DaylightNight

Daylight runs from about 11 h 42 min at the start of January to 11 h 42 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 0 minutes over January. Sunrise moves from 6:22 AM to 6:29 AM, and sunset from 6:01 PM to 6:14 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202531
Daylight (h)Sunrise (AM)Sunset (PM)
111.76:226:01
211.76:226:02
311.76:226:02
411.76:236:03
511.76:236:03
611.76:246:04
711.76:246:04
811.76:246:05
911.76:256:05
1011.76:256:05
1111.76:256:06
1211.76:266:06
1311.76:266:07
1411.76:266:07
1511.76:266:08
1611.76:276:08
1711.76:276:09
1811.76:276:09
1911.76:286:09
2011.76:286:10
2111.76:286:10
2211.76:286:11
2311.76:286:11
2411.76:296:11
2511.76:296:12
2611.76:296:12
2711.76:296:12
2811.76:296:13
2911.76:296:13
3011.76:296:13
3111.76:296:14

Solar energy in January

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in January, about 5.53 kWh/m².

For context, solar energy here swings from a low near 4.83 kWh/m² to a high of 6.46 kWh/m² in March across the year — January's 5.53 kWh/m² falls in the middle.

0246151015202531
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.4Bright
105.4Bright
115.4Bright
125.4Bright
135.5Bright
145.5Bright
155.5Bright
165.5Bright
175.6Bright
185.6Bright
195.6Bright
205.6Bright
215.7Bright
225.7Bright
235.7Bright
245.7Bright
255.7Bright
265.7Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
315.8Bright
Planning a trip in January

Hazard calendar for Mirissa

In seasonPeak

None of Mirissa's seasonal hazards are active in January. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Mirissa 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 January a good time to visit Mirissa?

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

4.7
Sightseeing
1st-best month of the year
6.2
Beach & pool
1st-best month of the year

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

What to pack for Mirissa in January

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

In January, Mirissa sees daytime highs around 29°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 15 days see rain.

light clothesrain gearsun protection

Sea temperature near Mirissa in January

The nearest coast averages about 28°C in January — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore 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 Mirissa in January

LowModerateHighVery highExtreme

Clear-sky midday UV in January peaks around 9 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Mirissa 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 Mirissa in January

GoodModeratePoorUnhealthyVery unhealthy

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

Air quality in Mirissa 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 Mirissa?

Mirissa sits at 5.9°N, 80.5°E, 0 m above sea level, in Sri Lanka. The nearest listed city is Weligama, 4.0 km away.

UnawatunaGalleBeliattaAmbalangodaAmbalantota

Topography around Mirissa

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

Within 3 km, the terrain around Mirissa has only modest variations in elevation — a maximum elevation change of 57 m around an average of 5 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 291 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,507 m.

The land around Mirissa is covered by water (60%) and trees (34%) within 3 km, water (54%) and trees (37%) within 16 km, and trees (52%) and water (44%) within 80 km.

3 km
57 m
16 km
291 m
80 km
1,507 m
treesgrasslandcroplandartificial surfaceswaterwetland
January weather nearby: Weligama 4.0 km · Matara 9.0 km · Devinuwara 15 km · Unawatuna 24 km · Galle 30 km · Beliatta 32 km · Ambalangoda 55 km · Ambalantota 65 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 Mirissa (5.9466°, 80.4583°, 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).