Ulaanbaatar weather in September
September in Ulaanbaatar: cool, a little rain, with clean air — an excellent time to visit.
#4 of 12 months in Ulaanbaatar · #278 of 604 destinations to visit in September · comfort 82/100 (tier A)
Updated June 2026 · climate normals from ERA5 reanalysis
Ulaanbaatar climate normals — September
| Daytime high | 17°C / 63°F | 🙂 cool |
|---|---|---|
| Nighttime low | 4°C / 40°F | |
| Feels like (high) | 14°C / 57°F | |
| Rainfall | 39 mm / 1.5 in | 🌦 some rain |
| Rainy days | 7 days | |
| Humidity | 64% | 💧 humid |
| Dew point | 3°C / 38°F | |
| Sunshine | 10 h/day | |
| Daylight | 12.6 h | |
| Wind | 16 km/h / 10 mph | |
| Snowfall | 3.7 cm / 1.5 in | |
| Air quality (US AQI) | 36 | 🍃 good |
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
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Ulaanbaatar in September — FAQ
- Is September a good time to visit Ulaanbaatar?
- September in Ulaanbaatar: cool, a little rain, with clean air — an excellent time to visit. It ranks #4 of 12 months for Ulaanbaatar on SeasonMap's comfort score (82/100).
- What is the weather like in Ulaanbaatar in September?
- In September, Ulaanbaatar averages a daily high of 17.3°C and a low of 4.2°C, with about 39.1 mm of rain over roughly 7.4 rainy days.
- What is the air quality in Ulaanbaatar in September?
- Ulaanbaatar has a mean US Air Quality Index of about 36 in September.
- Does it snow in Ulaanbaatar in September?
- Ulaanbaatar sees roughly 3.7 cm of snowfall in September.