Weather Phnom Penh Today – Temperature, Rain & Hourly Forecast
Monday, 21/09/2026
- High/Low
- 31°/25°
- Humidity
- 83%
- Wind
- 10 km/h
- Rainfall
- 10.1 mm
- UV index
- 4.6
- Pressure
- 1012 hPa
- Sunrise
- 05:49
- Sunset
- 17:57
Today
Summary
Today in Phnom Penh runs between 25 and 31°C, under moderate showers.
Expect rain near 00:00–21:00 totalling 9.6 mm.
UV peaks at 4.6 around 14:00 — wear a hat for longer stints outdoors.
At 83% humidity it feels like 32°C.
Winds of 11 km/h from the north.
Temperatures ease off, bottoming out at 24°C on Tuesday 22/09.
The wettest day ahead is Thursday 24/09 with about 23 mm.
Sunrise 05:49, sunset 17:57.
Local climate notes
Phnom Penh sits at the confluence of the Mekong, Tonlé Sap and Bassac rivers, which keeps humidity consistently higher than inland provinces at the same latitude. Wet-season rain is convective and typically arrives mid-afternoon: clear until noon, then an hour of heavy downpour, worst in Mean Chey and Chbar Ampov where drainage is weakest. From August to October the Tonlé Sap backs up and riverside streets flood locally after heavy rain, even when the rainfall total itself is unremarkable.
— Ban biên tập KhmerMeteo · Meteorological data editors
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48-hour forecast
Days ahead
| Today | Low/High | Chance of rain | Rainfall | |
|---|---|---|---|---|
| Today 21/09 | Moderate showers | 25°31° | 100% | 10.1 mm |
| Tomorrow 22/09 | Thunderstorm | 24°31° | 100% | 17.7 mm |
| Wednesday 23/09 | Thunderstorm | 25°30° | 100% | 22.4 mm |
| Thursday 24/09 | Moderate showers | 25°27° | 100% | 22.9 mm |
| Friday 25/09 | Thunderstorm | 24°30° | 98% | 8.7 mm |
Monthly averages
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Upstream rainfall · Mekong
- Past 72 hours
- 39 mm
- Next 72 hours
- 30 mm
- Status
- Slightly elevated
- Water may arrive
- 23/09
| Upstream sampling points | Past 72 hours | Next 72 hours |
|---|---|---|
| Luang Prabang, Laos | 48 mm | 2 mm |
| Vientiane, Laos | 34 mm | 27 mm |
| Savannakhet, Laos | 29 mm | 13 mm |
| Pakse, Laos | 41 mm | 42 mm |
| Nakhon Phanom, TH | 24 mm | 11 mm |
| Ubon Ratchathani, TH | 60 mm | 83 mm |
This measures upstream rainfall, not river level. Official levels and discharge come from the Mekong River Commission (MRC). Upstream rainfall causes the level, and is visible several days earlier. MRC
Upstream rainfall · Bassac
- Past 72 hours
- 45 mm
- Next 72 hours
- 68 mm
- Status
- Elevated
- Water may arrive
- 26/09
| Upstream sampling points | Past 72 hours | Next 72 hours |
|---|---|---|
| Kratie | 53 mm | 79 mm |
| Pakse, Laos | 41 mm | 42 mm |
| Stung Treng | 39 mm | 83 mm |
This measures upstream rainfall, not river level. Official levels and discharge come from the Mekong River Commission (MRC). Upstream rainfall causes the level, and is visible several days earlier. MRC