Phnom Penh weather in September
September is one of the least pleasant months in Phnom Penh: highs of 30°C (86°F) and about 190 mm (7.5 in) of rain on average. Nights average 24°C (75°F) and cloud cover 90% (NASA POWER, 2001–2025 averages). It is the 2nd wettest month of the year and the 2nd coolest. Compared with August, it is about as warm and about as wet; October brings highs of 30°C (86°F) and 167 mm (6.6 in) of rain.
Figures are long-term averages for Phnom Penh, the largest city in Phnom Penh. See below for other places.
Is September a good time to visit Phnom Penh?
least pleasant month Weather score 50/100.
September is one of the least pleasant months for weather in Phnom Penh. For better conditions, consider Nov–Jan.
Does it rain a lot in Phnom Penh in September?
Yes, it is one of the rainy months: about 190 mm (7.5 in) falls in an average September. It is the 2nd wettest month of the year.
How warm is Phnom Penh in September?
Days average 30°C (86°F) and nights 24°C (75°F).
Phnom Penh weather by month
| Month | High | Low | Rain | Cloud | Weather |
|---|---|---|---|---|---|
| January | 34°C (93°F) | 22°C (71°F) | 16 mm | 51% | best |
| February | 36°C (97°F) | 23°C (74°F) | 11 mm | 46% | fair |
| March | 37°C (99°F) | 25°C (77°F) | 30 mm | 56% | fair |
| April | 37°C (98°F) | 26°C (79°F) | 62 mm | 67% | least pleasant |
| May | 34°C (93°F) | 25°C (78°F) | 129 mm | 83% | least pleasant |
| June | 32°C (89°F) | 25°C (76°F) | 190 mm | 85% | least pleasant |
| July | 31°C (87°F) | 24°C (75°F) | 163 mm | 88% | least pleasant |
| August | 30°C (87°F) | 24°C (75°F) | 167 mm | 90% | least pleasant |
| September | 30°C (86°F) | 24°C (75°F) | 190 mm | 90% | least pleasant |
| October | 30°C (86°F) | 24°C (75°F) | 167 mm | 81% | least pleasant |
| November | 31°C (87°F) | 23°C (73°F) | 89 mm | 71% | best |
| December | 32°C (89°F) | 22°C (71°F) | 28 mm | 63% | best |
Sources: 2001–2025 monthly averages from NASA POWER (MERRA-2 reanalysis). Page updated . How we rate months
Weather across Phnom Penh in September
Weather can differ a lot within Phnom Penh: coasts, hills and mountains each have their own climate.
| Place | High | Low | Rain | Weather |
|---|---|---|---|---|
| Phnom Penh | 30°C (86°F) | 24°C (75°F) | 190 mm | least pleasant |
| Dangkao | 30°C (86°F) | 24°C (75°F) | 190 mm | least pleasant |
| Boeng Kak Pir | 30°C (86°F) | 24°C (75°F) | 190 mm | least pleasant |
| Chrang Chamreh Muoy | 30°C (86°F) | 24°C (75°F) | 190 mm | least pleasant |