Climate and average weather in Simunjan

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

Best: late May to early October

Over the course of the year, the temperature in Simunjan typically varies from 24°C to 32°C, and is rarely below 23°C or above 34°C. May is the hottest month of the year, while January is the coldest.

Based on the travel score, the best times of year to visit Simunjan for warm-weather activities are from early January to late March and late May to early October.

Hottest
May
32°
Coldest
Jan
24°
Wettest
Jan
385 mm
Driest
Jul
179 mm
Rain / yr
3290 mm
310 wet days
Daylight
11.9–12.1 h
shortest–longest
Elevation
7 m
1.4°N
Clearest
Jul
77% cloud

Simunjan 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 May to early October.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

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

Temperatures in Simunjan stay fairly even through the year, without a distinct hot or cool season. The warmest month is May, with an average high of 32°C and low of 25°C; the coolest is January, with an average low of 24°C and high of 30°C.

Days typically run about 7°C warmer than nights year-round.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan3024
Feb3024
Mar3124
Apr3224
May3225
Jun3224
Jul3224
Aug3224
Sep3224
Oct3124
Nov3124
Dec3124

How hot and cold Simunjan 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, Simunjan feels like about 41°C (around May 17). Nearly every day a year carries some heat stress, and 85 of them tip into dangerous heat (feels-like above 39°C), peaking in May.

20°25°30°35°40°45°JanFebMarAprMayJunJulAugSepOctNovDecdangerous heat
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan35302424
Feb35302424
Mar38312424
Apr40322424
May40322525
Jun40322424
Jul38322424
Aug38322424
Sep38322424
Oct38312424
Nov38312424
Dec37312424

Average hourly temperature in Simunjan

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 May 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

Simunjan 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
Jan30° / 24°38528.711.92.7
Feb30° / 24°29224.4122.8
Mar31° / 24°26627.9122.5
Apr32° / 24°26127.5122.3
May32° / 25°23726.212.12.4
Jun32° / 24°19521.912.12.8
Jul32° / 24°17919.912.13.0
Aug32° / 24°20721.8122.8
Sep32° / 24°25524.7122.6
Oct31° / 24°30828.7122.4
Nov31° / 24°32929.111.92.3
Dec31° / 24°37629.311.92.5

Chance of rain

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

Simunjan gets about 3290 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 7.5 months, from around Sep 27 to May 11, peaking in November at about 97% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Aug 1.

January is the wettest month by volume, with 385 mm over about 29 wet days; July is the driest, with 179 mm.

0%10%20%30%40%50%60%70%80%90%100%110%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetNov 14 · 97%Aug 1 · 61%
Rain on a day (%)Rain days
Jan9229
Feb8724
Mar9028
Apr9128
May8426
Jun7322
Jul6420
Aug7122
Sep8325
Oct9229
Nov9729
Dec9529

Monthly rainfall

Over a full year, Simunjan collects about 3290 mm of rain across 310 wet days — roughly 274 mm in an average month.

It doesn’t fall evenly. January is the wettest month with 385 mm, while July is the driest at just 179 mm. The three wettest months alone bring about 33% of the year’s total.

050100150200250300350400450JanFebMarAprMayJunJulAugSepOctNovDec385292266261237195179207255308329376
Rainfall (mm)Rain days
Jan38529
Feb29224
Mar26628
Apr26128
May23726
Jun19522
Jul17920
Aug20722
Sep25525
Oct30829
Nov32929
Dec37629

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

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

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

The clearer part of the year begins around April 13 and lasts for 5.0 months, ending around September 12. The clearest month is July, when the sky is clear, mostly clear, or partly cloudy 24% of the time on average.

The cloudier part of the year begins around September 13 and lasts for 7.0 months, ending around April 12. The cloudiest month is December, when it is overcast or mostly cloudy 99% 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%JanFebMarAprMayJunJulAugSepOctNovDecJun 21 · 26%Dec 20 · 0%partly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan397
Feb496
Mar793
Apr1090
May1783
Jun2377
Jul2476
Aug1585
Sep1090
Oct595
Nov397
Dec199

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. Close to the equator, Simunjan barely changes through the year: days stay near 12 h 06 min of light in every season.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan11.96:486:44
Feb12.06:536:50
Mar12.06:476:46
Apr12.06:366:38
May12.16:316:35
Jun12.16:356:40
Jul12.16:406:45
Aug12.06:406:42
Sep12.06:316:32
Oct12.06:236:21
Nov11.96:246:20
Dec11.96:366:31

Sunny days

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

Simunjan gets about 1 sunny days a month gloomy — and it barely shifts through the year, holding between 0 and 3 days every month. Clear skies here are a flat line, not a season.

05JanFebMarAprMayJunJulAugSepOctNovDecgloomyJul 83 daysFeb 140 days
Sunny daysSky
Jan0Gloomy
Feb0Gloomy
Mar0Gloomy
Apr1Gloomy
May2Gloomy
Jun2Gloomy
Jul2Gloomy
Aug1Gloomy
Sep1Gloomy
Oct0Gloomy
Nov0Gloomy
Dec0Gloomy

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.

Simunjan 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 100% 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%JanFebMarAprMayJunJulAugSepOctNovDecmiserableoppressive
Muggy (%)Oppressive (%)Miserable (%)
Jan04852
Feb04951
Mar02872
Apr0991
May0793
Jun02178
Jul14554
Aug14752
Sep03862
Oct03169
Nov02773
Dec03565

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.

Wind in Simunjan is steady company: average speeds sit near 5 km/hcalm — in every month of the year, with no meaningful windy or calm season.

0510JanFebMarAprMayJunJulAugSepOctNovDeccalmFeb 3 · 7 km/hApr 25 · 5 km/h
Wind speed (km/h)Feels
Jan6calm
Feb6calm
Mar5calm
Apr5calm
May5calm
Jun5calm
Jul5calm
Aug5calm
Sep5calm
Oct5calm
Nov5calm
Dec6calm

Best time to visit Simunjan

TravelBeach/poolTemperatureCloudsPrecipitation

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

Around late September, Simunjan is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

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. In Simunjan it holds close to 3.0 all year, so any month is about as good as another for general outdoor tourist activities.

0246810JanFebMarAprMayJunJulAugSepOctNovDectravel scoretemperaturecloudsprecipitation

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
Jan2.7poor
Feb2.8poor
Mar2.5poor
Apr2.3poor
May2.4poor
Jun2.8poor
Jul3.0poor
Aug2.8poor
Sep2.6poor
Oct2.4poor
Nov2.3poor
Dec2.5poor

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best times of year to visit Simunjan for hot-weather activities run from late January to early March and again from mid May to late September, with a peak score in the last week of July.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebest timebeach/pool scoretemperaturecloudsprecipitationJul 31 · 4.9

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 Simunjan, 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.

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

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In May, Simunjan sees daytime highs around 32°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 26 days see rain.

Sea temperature near Simunjan

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

The sea at the nearest coast (about 30 km away) is warmest in June at about 30°C and coldest in February near 28°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
Jan28Tropical
Feb28Tropical
Mar29Tropical
Apr30Tropical
May30Tropical
Jun30Tropical
Jul30Tropical
Aug30Tropical
Sep30Tropical
Oct30Tropical
Nov30Tropical
Dec29Tropical

UV index (midday) in Simunjan 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 Simunjan peaks around February 19 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 13 at about 11 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeFeb 19UV 15Jul 13UV 11
UV index (midday)Level
Jan14Extreme
Feb16Extreme
Mar15Extreme
Apr15Extreme
May13Extreme
Jun11Extreme
Jul11Extreme
Aug12Extreme
Sep12Extreme
Oct14Extreme
Nov12Extreme
Dec11Extreme

Average hourly UV index in Simunjan

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 February 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)
Jan86.5
Feb86.5
Mar8.56.5
Apr86.5
May86
Jun7.55.5
Jul7.55.5
Aug86
Sep86
Oct86
Nov7.55.5
Dec7.55.5

Air quality in Simunjan 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 Simunjan is worst in September — around 32 µg/m³ PM2.5 (moderate), about 3.1× the cleanest month (January, 10 µg/m³).

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

010203040JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1131 µg/m³Jan 1510 µg/m³
PM2.5 (µg/m³)Level
Jan10Good
Feb11Good
Mar13Moderate
Apr13Moderate
May12Moderate
Jun13Moderate
Jul21Moderate
Aug29Moderate
Sep32Moderate
Oct18Moderate
Nov12Good
Dec11Good
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Simunjan 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. Simunjan banks about 6,464 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around May.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan524
Feb476
Mar545
Apr542
May569
Jun545
Jul561
Aug561
Sep535
Oct547
Nov526
Dec534

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.

Simunjan receives about 5.0 kWh/m² a day of solar energy — bright — and it stays remarkably steady, holding between 4.3 and 5.4 kWh/m² all year. For solar panels, output here is a flat line, not a seasonal wave.

01234567JanFebMarAprMayJunJulAugSepOctNovDecdimmoderatebrightintenseAug 85.4 kWhDec 274.3 kWh
Solar energy (kWh/m²)Level
Jan4.5Bright
Feb4.8Bright
Mar5.2Bright
Apr5.3Bright
May5.1Bright
Jun5.0Bright
Jul5.2Bright
Aug5.4Bright
Sep5.3Bright
Oct5.0Bright
Nov4.6Bright
Dec4.4Bright

Where is Simunjan?

Simunjan sits at 1.4°N, 110.8°E, 7 m above sea level, in Malaysia. The nearest listed city is Serian, 32 km away.

Topography around Simunjan

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

Within 3 km, the terrain around Simunjan has only modest variations in elevation — a maximum elevation change of 23 m around an average of 7 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 391 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,408 m.

The land around Simunjan is covered by trees (66%) within 3 km, trees (85%) within 16 km, and trees (71%) and water (25%) within 80 km.

3 km
23 m
16 km
391 m
80 km
1,408 m
treesshrubsgrasslandartificial surfaceswatermangroves
Nearby: Serian 32 km · Siburan 39 km · Kuching 50 km · Tebedu 58 km · Bau 67 km · Saratok 76 km · Sri Aman 80 km · Betong 85 km

Malaysia travel facts

Travel advisory
Level 1
Exercise Normal Precautions
Power plugs
Type C / G / M
230 V · 50 Hz
Prices
≈ 32% of US
price level, 2025
GDP per capita
$13,125
2025
Happiness
6.0 / 10
World Happiness, 2025
Safe drinking water
95%
of population, 2024
Homicide rate
0.7
per 100k, 2023
Road deaths
22.5
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
High
EF EPI 581
Religion
Muslim 64%Buddhist 19%Christian 9%Hindu 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 Simunjan (1.3833°, 110.75°, 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. 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).