Climate averages 1991–2020
Udon Thani weather
in September.
A hot, very wet month: the 8th warmest and the 11th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a hot month in Udon Thani: daytime highs average 29.9°C and nights cool to about 23.7°C. By daytime temperature it is the 8th warmest of the 12 months.
Expect about 276 mm of rain on roughly 25 days, which makes September a very wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 12 h 15 min on an average September day.
The nearest other city in this atlas is Vientiane (64 km away). In September its highs average 29.6°C, about as warm as Udon Thani, with 300 mm of rain.
Among the 46 cities listed in Thailand, Udon Thani ranks joint 33rd of 46 for the warmest September highs and 38th of 46 for the driest September (rainfall, lowest first). The mean September high of those 46 cities is 30.3°C; Udon Thani is 0.5°C cooler than that mean.
From September to October, average highs fall by 0.5°C to 29.4°C, and monthly rainfall falls from 276 mm to 96 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
Udon Thani climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 28.0°C17.1°C | 17.1°C | 7.6 | 1.5 | 11.211 h |
| February | 30.5°C19.1°C | 19.1°C | 14 | 2.4 | 11.612 h |
| March | 33.1°C22.3°C | 22.3°C | 31 | 5.8 | 12.012 h |
| April | 34.3°C24.7°C | 24.7°C | 62 | 10.4 | 12.513 h |
| May | 32.6°C25.1°C | 25.1°C | 211 | 21.8 | 12.913 h |
| June | 31.4°C25.1°C | 25.1°C | 221 | 23.0 | 13.213 h |
| July | 30.6°C24.7°C | 24.7°C | 266 | 25.6 | 13.113 h |
| August | 30.1°C24.3°C | 24.3°C | 331 | 26.9 | 12.713 h |
| September, selected | 29.9°C23.7°C | 23.7°C | 276 | 24.5 | 12.212 h |
| October | 29.4°C22.3°C | 22.3°C | 96 | 11.8 | 11.812 h |
| November | 28.9°C20.0°C | 20.0°C | 20 | 2.9 | 11.311 h |
| December | 27.4°C17.3°C | 17.3°C | 6.4 | 0.9 | 11.111 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
- Vientiane in SeptemberLaos · 64 kmHigh 29.6°C · Low 23.8°C · 300 mm rain
- Khon Kaen in SeptemberThailand · 108 kmHigh 30.1°C · Low 23.8°C · 237 mm rain
- Sakon Nakhon in SeptemberThailand · 147 kmHigh 29.7°C · Low 23.7°C · 268 mm rain
- Thakhèk in SeptemberLaos · 217 kmHigh 29.4°C · Low 23.1°C · 317 mm rain
- Savannakhet in SeptemberLaos · 230 kmHigh 29.4°C · Low 23.3°C · 257 mm rain
- Nakhon Ratchasima in SeptemberThailand · 282 kmHigh 30.3°C · Low 23.7°C · 231 mm rain
- Ubon Ratchathani in SeptemberThailand · 327 kmHigh 29.9°C · Low 23.8°C · 273 mm rain
- Vinh in SeptemberVietnam · 338 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 Udon Thani) is explained once on the Udon Thani year overview and on the Sources, method and limits page.