Phnom Penh weather in September

In September, Phnom Penh sees average daytime highs of 32°C and overnight lows near 26°C, with 245 mm of rain across 27.2 wet days and about 12.1 hours of daylight. It is the 8th-warmest and 1st-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 h 12 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Phnom Penh's 12th-clearest and 9th-windiest month. For the whole year in context, see Phnom Penh's year-round climate.

Daytime high: 32°; 8th warmest
Overnight low: 26°; 6th coldest
Rainfall: 245 mm; 27.2 wet days
Daylight: 12 h 06 min; 5:53 AM – 5:57 PM
Cloud cover: 89%; 12th clearest
Wind: 8 km/h; 9th windiest
Solar energy: 4.69 kWh/m²
Travel score: 2.1; out of 10

Phnom Penh is capital of Cambodia.

Density: 2,319/km²; people per km²
Founded: 1372

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

← August Phnom Penh year-round climate October →Best places to visit in September

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

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 Phnom Penh reaches about 32°C in the afternoon and slips back to 26°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 34°C. Set against its neighbours, September runs on par with August and on par with October.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°C)	33	33	33	33	33	33	33	33	33	32	32	32	32	32	32	32	32	32	32	32	32	32	32	32	32	32	32	32	32	32
Avg low (°C)	26	26	26	26	26	26	26	26	26	26	26	26	26	26	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25

	Avg high (°C)	Avg low (°C)
1	33	26
2	33	26
3	33	26
4	33	26
5	33	26
6	33	26
7	33	26
8	33	26
9	33	26
10	32	26
11	32	26
12	32	26
13	32	26
14	32	26
15	32	25
16	32	25
17	32	25
18	32	25
19	32	25
20	32	25
21	32	25
22	32	25
23	32	25
24	32	25
25	32	25
26	32	25
27	32	25
28	32	25
29	32	25
30	32	25

How September really feels in Phnom Penh

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 feel dangerously hot (≥ 39°C)

Days feeling ≤ 0°C

wind chill below the day's low

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

Phnom Penh weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 1st-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	32° / 23°	15	3	11.4	4.5
Feb	34° / 24°	8	1.7	11.6	3.8
Mar	35° / 26°	36	6.2	11.9	2.7
Apr	36° / 27°	81	14.6	12.2	1.9
May	35° / 27°	154	22.7	12.5	1.8
Jun	34° / 26°	154	24.3	12.7	2.0
Jul	33° / 26°	154	25.6	12.6	2.2
Aug	33° / 26°	178	25.9	12.4	2.1
Sep	32° / 26°	245	27.2	12.1	2.1
Oct	32° / 25°	244	24.7	11.7	2.6
Nov	32° / 25°	78	11.1	11.5	3.9
Dec	31° / 24°	27	5.1	11.3	4.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 2% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 5% of September, with mostly cloudy or overcast conditions the remaining 93%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	6	6	6	6	6	5	5	5	5	5	5	5	5	6	6	6	6	6	6	7	8	8	8	8	9	9	9	9	9	9
Cloudier (%)	94	94	94	94	94	95	95	95	95	95	95	95	95	94	94	94	94	94	94	93	92	92	92	92	91	91	91	91	91	91

	Clearer (%)	Cloudier (%)
1	6	94
2	6	94
3	6	94
4	6	94
5	6	94
6	5	95
7	5	95
8	5	95
9	5	95
10	5	95
11	5	95
12	5	95
13	5	95
14	6	94
15	6	94
16	6	94
17	6	94
18	6	94
19	6	94
20	7	93
21	8	92
22	8	92
23	8	92
24	8	92
25	9	91
26	9	91
27	9	91
28	9	91
29	9	91
30	9	91

Chance of precipitation in September

Any precipitation

Phnom Penh gets around 245 mm of rain over 27.2 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 91% and peaks near 93% on the wettest days.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	90	90	90	90	90	90	90	90	90	90	90	90	90	90	90	90	90	90	90	91	91	91	91	91	91	92	92	92	92	93

	Rain chance (%)
1	90
2	90
3	90
4	90
5	90
6	90
7	90
8	90
9	90
10	90
11	90
12	90
13	90
14	90
15	90
16	90
17	90
18	90
19	90
20	91
21	91
22	91
23	91
24	91
25	91
26	92
27	92
28	92
29	92
30	93

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 86% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Oppressive (%)	20	20	20	20	20	20	19	19	18	18	17	16	16	15	14	14	13	12	12	11	11	10	10	9	9	9	9	8	8	8
Miserable (%)	80	80	80	80	80	80	81	81	82	82	83	84	84	85	86	86	87	88	88	89	89	90	90	91	91	91	91	92	92	92

	Oppressive (%)	Miserable (%)
1	20	80
2	20	80
3	20	80
4	20	80
5	20	80
6	20	80
7	19	81
8	19	81
9	18	82
10	18	82
11	17	83
12	16	84
13	16	84
14	15	85
15	14	86
16	14	86
17	13	87
18	12	88
19	12	88
20	11	89
21	11	89
22	10	90
23	10	90
24	9	91
25	9	91
26	9	91
27	9	91
28	8	92
29	8	92
30	8	92

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 6 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (km/h)	9	9	9	9	8	8	8	8	8	8	8	8	8	8	8	8	8	8	7	7	7	7	7	7	7	7	6	6	6	6
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (km/h)	Feels
1	9	calm
2	9	calm
3	9	calm
4	9	calm
5	8	calm
6	8	calm
7	8	calm
8	8	calm
9	8	calm
10	8	calm
11	8	calm
12	8	calm
13	8	calm
14	8	calm
15	8	calm
16	8	calm
17	8	calm
18	8	calm
19	7	calm
20	7	calm
21	7	calm
22	7	calm
23	7	calm
24	7	calm
25	7	calm
26	7	calm
27	6	calm
28	6	calm
29	6	calm
30	6	calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 12 min at the start of September to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 18 minutes over September. Sunrise moves from 5:53 AM to 5:52 AM, and sunset from 6:07 PM to 5:47 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	12.2	12.2	12.2	12.2	12.2	12.2	12.2	12.2	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	11.9	11.9	11.9	11.9
Sunrise (AM)	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:53	5:52	5:52	5:52	5:52	5:52	5:52	5:52	5:52
Sunset (PM)	6:07	6:06	6:05	6:05	6:04	6:03	6:03	6:02	6:01	6:01	6:00	5:59	5:59	5:58	5:57	5:57	5:56	5:55	5:54	5:54	5:53	5:52	5:52	5:51	5:50	5:50	5:49	5:48	5:48	5:47

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	12.2	5:53	6:07
2	12.2	5:53	6:06
3	12.2	5:53	6:05
4	12.2	5:53	6:05
5	12.2	5:53	6:04
6	12.2	5:53	6:03
7	12.2	5:53	6:03
8	12.2	5:53	6:02
9	12.1	5:53	6:01
10	12.1	5:53	6:01
11	12.1	5:53	6:00
12	12.1	5:53	5:59
13	12.1	5:53	5:59
14	12.1	5:53	5:58
15	12.1	5:53	5:57
16	12.1	5:53	5:57
17	12.1	5:53	5:56
18	12.0	5:53	5:55
19	12.0	5:53	5:54
20	12.0	5:53	5:54
21	12.0	5:53	5:53
22	12.0	5:53	5:52
23	12.0	5:52	5:52
24	12.0	5:52	5:51
25	12.0	5:52	5:50
26	12.0	5:52	5:50
27	11.9	5:52	5:49
28	11.9	5:52	5:48
29	11.9	5:52	5:48
30	11.9	5:52	5:47

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.69 kWh/m².

For context, solar energy here swings from a low near 4.59 kWh/m² to a high of 6.14 kWh/m² in April across the year — September's 4.69 kWh/m² sits near the bottom.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	5.0	5.0	5.0	4.9	4.9	4.9	4.8	4.8	4.8	4.8	4.7	4.7	4.7	4.7	4.6	4.6	4.6	4.6	4.6	4.6	4.5	4.5	4.5	4.5	4.5	4.5	4.5	4.5	4.5	4.5
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	5.0	Bright
2	5.0	Bright
3	5.0	Bright
4	4.9	Bright
5	4.9	Bright
6	4.9	Bright
7	4.8	Bright
8	4.8	Bright
9	4.8	Bright
10	4.8	Bright
11	4.7	Bright
12	4.7	Bright
13	4.7	Bright
14	4.7	Bright
15	4.6	Bright
16	4.6	Bright
17	4.6	Bright
18	4.6	Bright
19	4.6	Bright
20	4.6	Bright
21	4.5	Bright
22	4.5	Bright
23	4.5	Bright
24	4.5	Bright
25	4.5	Bright
26	4.5	Bright
27	4.5	Bright
28	4.5	Bright
29	4.5	Bright
30	4.5	Bright

Planning a trip in September

Hazard calendar for Phnom Penh

In seasonPeak

In September, Phnom Penh sits inside its pacific typhoon and rainy season season. The full year is below, with each hazard's peak months called out.

Phnom Penh sits in the Pacific typhoon belt; the season peaks July–October.

Phnom Penh's rainy season runs May–October, when most of the year's rain falls.

Pacific typhoon

Rainy season

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Is September a good time to visit Phnom Penh?

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

2.1

Sightseeing

8th-best month of the year

3.6

Beach & pool

12th-best month of the year

September is a weaker month for outdoor sightseeing in Phnom Penh.

What to pack for Phnom Penh in September

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

In September, Phnom Penh sees daytime highs around 32°C and nights near 26°C. Pack light clothes and rain gear. Worth having: sun protection. About 27 days see rain.

light clothesrain gearsun protection

UV index in Phnom Penh in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September 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 Phnom Penh peaks around August 18 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 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.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	10	11	12	12	11	12	12	14	13	10	9	9
Level	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Very high	Very high	Very high

	UV index (midday)	Level
Jan	10	Extreme
Feb	11	Extreme
Mar	12	Extreme
Apr	12	Extreme
May	11	Extreme
Jun	12	Extreme
Jul	12	Extreme
Aug	14	Extreme
Sep	13	Extreme
Oct	10	Very high
Nov	9	Very high
Dec	9	Very high

Air quality in Phnom Penh 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 Phnom Penh is worst in February — around 44 µg/m³ PM2.5 (poor), about 2.4× the cleanest month (August, 18 µg/m³).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	42	44	41	35	26	21	21	18	22	28	29	29
Level	Poor	Poor	Poor	Poor	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	PM2.5 (µg/m³)	Level
Jan	42	Poor
Feb	44	Poor
Mar	41	Poor
Apr	35	Poor
May	26	Moderate
Jun	21	Moderate
Jul	21	Moderate
Aug	18	Moderate
Sep	22	Moderate
Oct	28	Moderate
Nov	29	Moderate
Dec	29	Moderate

Location & terrain

Where is Phnom Penh?

Phnom Penh sits at 11.6°N, 104.9°E, 20 m above sea level, in Cambodia. The nearest listed city is Boeng Kak Pir, 3.0 km away.

Topography around Phnom Penh

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

Within 3 km, the terrain around Phnom Penh has only modest variations in elevation — a maximum elevation change of 25 m around an average of 13 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 59 m; within 80 km, large variations in elevation — a maximum elevation change of 713 m.

The land around Phnom Penh is covered by artificial surfaces (82%) within 3 km, artificial surfaces (25%) within 16 km, and cropland (70%) within 80 km.

3 km

25 m

artificial surfaces 82%

16 km

59 m

artificial surfaces 25%

80 km

713 m

cropland 70%

treesgrasslandcroplandartificial surfacesbare terrainwaterwetland

← August Phnom Penh year-round climate October →Best places to visit in September

September weather nearby: Boeng Kak Pir 3.0 km · Dangkao 7.0 km · Chrang Chamreh Muoy 8.0 km · Ta Khmau 10 km · Kandoeng 31 km · Phumĭ Yoŭl Toŭng 37 km · Phumĭ Véal Tônsay 39 km · Kampong Speu 45 km

Cambodia travel facts

Travel advisory: Level 2; Exercise Increased Caution
Power plugs: Type A / C / G; 230 V · 50 Hz
Prices: ≈ 34% of US; price level, 2025
GDP per capita: $2,872; 2025
Happiness: 4.5 / 10; World Happiness, 2025
Safe drinking water: 30%; of population, 2024
Homicide rate: 1.8; per 100k, 2011
Road deaths: 19.6; per 100k/yr, 2019
Income group: Lower middle; World Bank
English: Very low; EF EPI 390
Religion

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 Phnom Penh (11.5625°, 104.916°, elevation 20 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). 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).

	Avg high (°C)	Avg low (°C)
1	33	26
2	33	26
3	33	26
4	33	26
5	33	26
6	33	26
7	33	26
8	33	26
9	33	26
10	32	26
11	32	26
12	32	26
13	32	26
14	32	26
15	32	25
16	32	25
17	32	25
18	32	25
19	32	25
20	32	25
21	32	25
22	32	25
23	32	25
24	32	25
25	32	25
26	32	25
27	32	25
28	32	25
29	32	25
30	32	25

	Clearer (%)	Cloudier (%)
1	6	94
2	6	94
3	6	94
4	6	94
5	6	94
6	5	95
7	5	95
8	5	95
9	5	95
10	5	95
11	5	95
12	5	95
13	5	95
14	6	94
15	6	94
16	6	94
17	6	94
18	6	94
19	6	94
20	7	93
21	8	92
22	8	92
23	8	92
24	8	92
25	9	91
26	9	91
27	9	91
28	9	91
29	9	91
30	9	91

	Rain chance (%)
1	90
2	90
3	90
4	90
5	90
6	90
7	90
8	90
9	90
10	90
11	90
12	90
13	90
14	90
15	90
16	90
17	90
18	90
19	90
20	91
21	91
22	91
23	91
24	91
25	91
26	92
27	92
28	92
29	92
30	93

	Oppressive (%)	Miserable (%)
1	20	80
2	20	80
3	20	80
4	20	80
5	20	80
6	20	80
7	19	81
8	19	81
9	18	82
10	18	82
11	17	83
12	16	84
13	16	84
14	15	85
15	14	86
16	14	86
17	13	87
18	12	88
19	12	88
20	11	89
21	11	89
22	10	90
23	10	90
24	9	91
25	9	91
26	9	91
27	9	91
28	8	92
29	8	92
30	8	92

	Avg high (°C)	Avg low (°C)
1	33	26
2	33	26
3	33	26
4	33	26
5	33	26
6	33	26
7	33	26
8	33	26
9	33	26
10	32	26
11	32	26
12	32	26
13	32	26
14	32	26
15	32	25
16	32	25
17	32	25
18	32	25
19	32	25
20	32	25
21	32	25
22	32	25
23	32	25
24	32	25
25	32	25
26	32	25
27	32	25
28	32	25
29	32	25
30	32	25

	Clearer (%)	Cloudier (%)
1	6	94
2	6	94
3	6	94
4	6	94
5	6	94
6	5	95
7	5	95
8	5	95
9	5	95
10	5	95
11	5	95
12	5	95
13	5	95
14	6	94
15	6	94
16	6	94
17	6	94
18	6	94
19	6	94
20	7	93
21	8	92
22	8	92
23	8	92
24	8	92
25	9	91
26	9	91
27	9	91
28	9	91
29	9	91
30	9	91

	Rain chance (%)
1	90
2	90
3	90
4	90
5	90
6	90
7	90
8	90
9	90
10	90
11	90
12	90
13	90
14	90
15	90
16	90
17	90
18	90
19	90
20	91
21	91
22	91
23	91
24	91
25	91
26	92
27	92
28	92
29	92
30	93

	Oppressive (%)	Miserable (%)
1	20	80
2	20	80
3	20	80
4	20	80
5	20	80
6	20	80
7	19	81
8	19	81
9	18	82
10	18	82
11	17	83
12	16	84
13	16	84
14	15	85
15	14	86
16	14	86
17	13	87
18	12	88
19	12	88
20	11	89
21	11	89
22	10	90
23	10	90
24	9	91
25	9	91
26	9	91
27	9	91
28	8	92
29	8	92
30	8	92

	Avg high (°C)	Avg low (°C)
1	33	26
2	33	26
3	33	26
4	33	26
5	33	26
6	33	26
7	33	26
8	33	26
9	33	26
10	32	26
11	32	26
12	32	26
13	32	26
14	32	26
15	32	25
16	32	25
17	32	25
18	32	25
19	32	25
20	32	25
21	32	25
22	32	25
23	32	25
24	32	25
25	32	25
26	32	25
27	32	25
28	32	25
29	32	25
30	32	25

	Clearer (%)	Cloudier (%)
1	6	94
2	6	94
3	6	94
4	6	94
5	6	94
6	5	95
7	5	95
8	5	95
9	5	95
10	5	95
11	5	95
12	5	95
13	5	95
14	6	94
15	6	94
16	6	94
17	6	94
18	6	94
19	6	94
20	7	93
21	8	92
22	8	92
23	8	92
24	8	92
25	9	91
26	9	91
27	9	91
28	9	91
29	9	91
30	9	91

	Rain chance (%)
1	90
2	90
3	90
4	90
5	90
6	90
7	90
8	90
9	90
10	90
11	90
12	90
13	90
14	90
15	90
16	90
17	90
18	90
19	90
20	91
21	91
22	91
23	91
24	91
25	91
26	92
27	92
28	92
29	92
30	93

	Oppressive (%)	Miserable (%)
1	20	80
2	20	80
3	20	80
4	20	80
5	20	80
6	20	80
7	19	81
8	19	81
9	18	82
10	18	82
11	17	83
12	16	84
13	16	84
14	15	85
15	14	86
16	14	86
17	13	87
18	12	88
19	12	88
20	11	89
21	11	89
22	10	90
23	10	90
24	9	91
25	9	91
26	9	91
27	9	91
28	8	92
29	8	92
30	8	92