Climate averages 1991–2020
Sầm Sơn weather
in September.
A hot, very wet month: the 5th warmest and the wettest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Sầm Sơn: daytime highs average 29.5°C and nights cool to about 25.2°C. By daytime temperature it is the 5th warmest of the 12 months.
Expect about 368 mm of rain on roughly 20 days, which makes September a very wet month (the wettest month of the year). Daylight, from sunrise to sunset, lasts about 12 h 16 min on an average September day.
The nearest other city in this atlas is Thanh Hóa (16 km away). In September its highs average 29.8°C, about as warm as Sầm Sơn, with 289 mm of rain.
Among the 136 cities listed in Vietnam, Sầm Sơn ranks joint 100th of 136 for the warmest September highs and 132nd of 136 for the driest September (rainfall, lowest first). The mean September high of those 136 cities is 29.7°C; Sầm Sơn is 0.1°C cooler than that mean.
From September to October, average highs fall by 2.1°C to 27.4°C, and monthly rainfall falls from 368 mm to 241 mm.
The annual picture
September in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Sầm Sơn climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 19.8°C15.4°C | 15.4°C | 55 | 10.5 | 11.111 h |
| February | 21.2°C16.7°C | 16.7°C | 36 | 8.5 | 11.511 h |
| March | 23.8°C19.2°C | 19.2°C | 52 | 9.7 | 12.012 h |
| April | 27.3°C22.6°C | 22.6°C | 62 | 7.5 | 12.613 h |
| May | 30.3°C25.5°C | 25.5°C | 139 | 12.2 | 13.113 h |
| June | 32.0°C27.5°C | 27.5°C | 146 | 11.0 | 13.313 h |
| July | 31.7°C27.4°C | 27.4°C | 212 | 12.7 | 13.213 h |
| August | 30.9°C26.5°C | 26.5°C | 312 | 20.1 | 12.813 h |
| September, selected | 29.5°C25.2°C | 25.2°C | 368 | 20.1 | 12.312 h |
| October | 27.4°C22.9°C | 22.9°C | 241 | 16.2 | 11.712 h |
| November | 24.7°C19.9°C | 19.9°C | 82 | 9.9 | 11.211 h |
| December | 21.1°C16.3°C | 16.3°C | 53 | 8.9 | 11.011 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
September in nearby cities
- Thanh Hóa in SeptemberVietnam · 16 kmHigh 29.8°C · Low 24.8°C · 289 mm rain
- Nghi Sơn in SeptemberVietnam · 46 kmHigh 29.3°C · Low 24.4°C · 293 mm rain
- Hoàng Mai in SeptemberVietnam · 55 kmHigh 29.9°C · Low 24.8°C · 293 mm rain
- Hoa Lư in SeptemberVietnam · 59 kmHigh 30.0°C · Low 24.2°C · 289 mm rain
- Nam Định in SeptemberVietnam · 83 kmHigh 30.0°C · Low 24.5°C · 277 mm rain
- Phủ Lý in SeptemberVietnam · 90 kmHigh 30.0°C · Low 24.0°C · 274 mm rain
- Hưng Yên in SeptemberVietnam · 103 kmHigh 30.1°C · Low 24.2°C · 254 mm rain
- Vinh in SeptemberVietnam · 120 kmHigh 29.9°C · Low 25.0°C · 330 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Sầm Sơn) is explained once on the Sầm Sơn year overview and on the Sources, method and limits page.