Weather in Ulaanbaatar in September 2025
Average weather
Average temperature in Ulaanbaatar in September
Going from a maximum of +30°C during the day to a minimum of 0°C during the night, the temperature in September averages around +17°C.
The average maximum temperature goes down 47% by the end of the month, compared with the beginning of the month, from +28°C to +14°C.
Is Ulaanbaatar warm or cold in September?
Ulaanbaatar is typically mild in September.
Maximum temperatures go down compared to the previous month from +22°C to +16°C. The minimum temperature also goes down from +11°C to +4°C.
Pack a light jacket as it will be warm in the day and cool in the evenings.
Take a look at how September is compared to other months in Ulaanbaatar:
Climate in Ulaanbaatar in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +22°C | +16°C | +8°C | ||||
| Min. temperature | ||||||
| -1°C | -13°C | -24°C | ||||
| Max. temperature | ||||||
| +37°C | +31°C | +23°C | ||||
| Rainfall | ||||||
| 74 mm | 34 mm | 7 mm | ||||
| Wind | ||||||
| 2 m/s | 2 m/s | 2 m/s | ||||
| Humidity | ||||||
| 66% | 62% | 63% | ||||
| Air pressure | ||||||
| 1010 HPa | 1015 HPa | 1020 HPa | ||||
| Sunny days | ||||||
| 5 | 9 | 13 | ||||
| Cloudy days | ||||||
| 7 | 8 | 10 | ||||
| Rainy days | ||||||
| 15 | 11 | 3 | ||||
| Snowy days | ||||||
| 0 | 1 | 5 | ||||
September weather is still as good as in August. It’s getting colder in September. From +22°C in the day, the average maximum temperature lowers to +16°C. As September arrives, the amount of rainfall goes down. On average, the rainfall volume decreases from 74 mm to 34 mm. It feels drier, as humidity decreases from 66% to 62%. The average wind speed doesn’t change much during September, staying around 2 m/s. The good news is there are likely to be more sunny days in September, from 5 to 9.
October brings much the same weather, it remains good.
Wind
The average wind speed is 3 m/s getting up to 5 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Ulaanbaatar is gradually decreasing during September, going from 2 m/s to 1 m/s over the course of the month.
Rain
How was the weather last September in Ulaanbaatar?
Climate Change over Years
The climate in Ulaanbaatar in September has not changed much over the last 43 years.
The average temperature was the lowest in 1985 (+4°C) and the highest in 2007 (+9°C). The driest year was 2017 with only 192 mm of rainfall, and the wettest year was 1984 with 432 mm.
FAQ
Is September a good time to visit Ulaanbaatar?
Can you sunbathe in Ulaanbaatar in September?
Is Ulaanbaatar rainy in September?
Is it sunny in Ulaanbaatar in September?
Monthly weather in Ulaanbaatar
Source of the data
For this page, we’ve looked at the typical weather in Ulaanbaatar, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.