Climate averages 1991–2020
Ulan Bator weather
in May.
A mild, fairly dry month: the 4th warmest and the 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
May is a mild month in Ulan Bator: daytime highs average 15.8°C and nights cool to about 1.7°C. By daytime temperature it is the 4th warmest of the 12 months.
Expect about 34 mm of rain on roughly 7 days, which makes May a fairly dry month (the 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 15 h 08 min on an average May day.
The nearest other city in this atlas is Darhan (189 km away). In May its highs average 19.1°C, 3.3°C warmer than Ulan Bator, with 33 mm of rain.
Among the 3 cities listed in Mongolia, Ulan Bator ranks 2nd of 3 for the warmest May highs and 2nd of 3 for the driest May (rainfall, lowest first). The mean May high of those 3 cities is 16.8°C; Ulan Bator is 1.1°C cooler than that mean.
From May to June, average highs rise by 5.7°C to 21.4°C, and monthly rainfall rises from 34 mm to 55 mm.
The annual picture
May in context
Monthly precipitation
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
Ulan Bator climate table
| Month | Average highHigh / low | Average low | Precipitation mm/month | Wet days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | -12.4°C-24.8°C | -24.8°C | 1.5 | 0.5 | 8.99 h |
| February | -7.4°C-21.2°C | -21.2°C | 2.8 | 1.2 | 10.210 h |
| March | 0.9°C-11.9°C | -11.9°C | 7.3 | 2.2 | 11.912 h |
| April | 8.8°C-3.6°C | -3.6°C | 16 | 4.3 | 13.614 h |
| May, selected | 15.8°C1.7°C | 1.7°C | 34 | 6.7 | 15.115 h |
| June | 21.4°C8.4°C | 8.4°C | 55 | 9.5 | 16.016 h |
| July | 23.7°C11.9°C | 11.9°C | 66 | 11.2 | 15.616 h |
| August | 21.7°C9.8°C | 9.8°C | 68 | 10.7 | 14.314 h |
| September | 15.6°C3.0°C | 3.0°C | 39 | 7.2 | 12.613 h |
| October | 6.5°C-4.1°C | -4.1°C | 15 | 3.8 | 10.911 h |
| November | -3.7°C-13.5°C | -13.5°C | 6.1 | 2.1 | 9.39 h |
| December | -10.8°C-20.9°C | -20.9°C | 2.1 | 0.9 | 8.58 h |
Precipitation (rain or snow, as water) is the average of the 30 separate monthly totals. A wet 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
May in nearby cities
- Darhan in MayMongolia · 189 kmHigh 19.1°C · Low 4.5°C · 33 mm rain
- Erdenet in MayMongolia · 241 kmHigh 15.6°C · Low 2.7°C · 35 mm rain
- Ulan-Ude in MayRussia · 439 kmHigh 17.1°C · Low 3.1°C · 31 mm rain
- Irkutsk in MayRussia · 522 kmHigh 16.8°C · Low 3.3°C · 38 mm rain
- Angarsk in MayRussia · 559 kmHigh 17.4°C · Low 3.6°C · 33 mm rain
- Usol’ye-Sibirskoye in MayRussia · 585 kmHigh 17.2°C · Low 3.7°C · 34 mm rain
- Chita in MayRussia · 659 kmHigh 16.5°C · Low 2.9°C · 39 mm rain
- Bayan Nur in MayChina · 798 kmHigh 24.8°C · Low 10.0°C · 16 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 Ulan Bator) is explained once on the Ulan Bator year overview and on the Sources, method and limits page.