Simunjan weather in September

In September, Simunjan sees average daytime highs of 32°C and overnight lows near 24°C, with 255 mm of rain across 24.7 wet days and about 12 hours of daylight. It is the 6th-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 32°C through the month. The sky is clear or mostly clear about 2% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 hours at the start of September to 12 hours by month's end. Set against the rest of the year, September is Simunjan's 6th-clearest and 7th-windiest month. For the whole year in context, see Simunjan's year-round climate.

Daytime high
32°
6th warmest
Overnight low
24°
7th coldest
Rainfall
255 mm
24.7 wet days
Daylight
12 hours
6:31 AM – 6:32 PM
Cloud cover
85%
6th clearest
Wind
5 km/h
7th windiest
Solar energy
5.25 kWh/m²
Travel score
2.6
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 32°C through the month.

A typical September day in Simunjan reaches about 32°C in the afternoon and slips back to 24°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 33°C. Set against its neighbours, September runs on par with August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13224
23224
33224
43224
53224
63224
73224
83224
93224
103224
113224
123224
133224
143224
153224
163224
173224
183224
193224
203224
213224
223224
233224
243224
253224
263224
273224
283224
293224
303224

How September really feels in Simunjan

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.

Simunjan weather by month

How September compares with the rest of the year at a glance. September is the 6th-warmest and 8th-wettest month here — the current month is highlighted below.

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

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 2% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 8% of September, with mostly cloudy or overcast conditions the remaining 91%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
11189
21189
31189
41189
51189
61189
71090
81090
91090
101090
111090
121090
131090
141090
151090
161090
171090
181090
191090
20991
21991
22991
23892
24892
25892
26892
27892
28892
29892
30892

Chance of precipitation in September

Any precipitation

Simunjan gets around 255 mm of rain over 24.7 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 83% and peaks near 87% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
182
283
383
483
583
682
782
882
982
1081
1181
1281
1381
1481
1581
1681
1781
1882
1982
2082
2183
2283
2383
2484
2584
2685
2785
2886
2986
3087

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 62% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
14258
24357
34357
44357
54357
64357
74357
84357
94357
104357
114258
124258
134159
144060
153862
163763
173664
183565
193466
203367
213367
223268
233268
243268
253268
263268
273268
283268
293367
303367

Wind in September

Winds average 5 km/h in September.

Across September, daily wind ranges from about 5 km/h on the calmest days to 5 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
175calm
185calm
195calm
205calm
215calm
225calm
235calm
245calm
255calm
265calm
275calm
285calm
295calm
305calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 hours at the start of September to 12 hours by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 0 minutes over September. Sunrise moves from 6:36 AM to 6:27 AM, and sunset from 6:38 PM to 6:26 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.06:366:38
212.06:366:37
312.06:356:37
412.06:356:36
512.06:356:36
612.06:346:36
712.06:346:35
812.06:346:35
912.06:336:34
1012.06:336:34
1112.06:336:34
1212.06:326:33
1312.06:326:33
1412.06:326:32
1512.06:316:32
1612.06:316:32
1712.06:316:31
1812.06:306:31
1912.06:306:30
2012.06:306:30
2112.06:296:29
2212.06:296:29
2312.06:296:29
2412.06:286:28
2512.06:286:28
2612.06:286:28
2712.06:286:27
2812.06:276:27
2912.06:276:26
3012.06:276:26

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.25 kWh/m².

For context, solar energy here swings from a low near 4.38 kWh/m² to a high of 5.37 kWh/m² in August across the year — September's 5.25 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.2Bright
55.2Bright
65.2Bright
75.2Bright
85.2Bright
95.2Bright
105.3Bright
115.3Bright
125.3Bright
135.3Bright
145.3Bright
155.3Bright
165.3Bright
175.3Bright
185.3Bright
195.3Bright
205.3Bright
215.3Bright
225.3Bright
235.3Bright
245.2Bright
255.2Bright
265.2Bright
275.2Bright
285.2Bright
295.2Bright
305.1Bright
Planning a trip in September

Is September a good time to visit Simunjan?

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

2.6
Sightseeing
6th-best month of the year
4.0
Beach & pool
4th-best month of the year

September is a weaker month for outdoor sightseeing in Simunjan.

What to pack for Simunjan in September

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

In September, Simunjan sees daytime highs around 32°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 25 days see rain.

light clothesrain gearsun protection

Sea temperature near Simunjan in September

The nearest coast averages about 30°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 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 in Simunjan 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 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

Air quality in Simunjan 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 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
Location & terrain

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
September weather 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).