Climate averages 1991–2020
Ulan Bator weather
in December.
A freezing month with very little precipitation: the 11th warmest and the 2nd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a freezing month in Ulan Bator: daytime highs average -10.8°C and nights cool to about -20.9°C. By daytime temperature it is the 11th warmest of the 12 months.
Expect about 2.1 mm of precipitation on fewer than one day, which makes December a month with very little precipitation (the 2nd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 8 h 28 min on an average December day.
The nearest other city in this atlas is Darhan (189 km away). In December its highs average -10.8°C, about as warm as Ulan Bator, with 4.1 mm of precipitation.
Among the 3 cities listed in Mongolia, Ulan Bator ranks joint 2nd of 3 for the warmest December highs and 1st of 3 for the driest December (precipitation, lowest first). The mean December high of those 3 cities is -10.5°C; Ulan Bator is 0.3°C cooler than that mean.
From December to January, average highs fall by 1.6°C to -12.4°C, and monthly precipitation falls from 2.1 mm to 1.5 mm.
The annual picture
December 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 | 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, selected | -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
December in nearby cities
- Darhan in DecemberMongolia · 189 kmHigh -10.8°C · Low -20.6°C · 4.1 mm precipitation
- Erdenet in DecemberMongolia · 241 kmHigh -10.0°C · Low -18.7°C · 3.2 mm precipitation
- Ulan-Ude in DecemberRussia · 439 kmHigh -13.7°C · Low -22.6°C · 6.6 mm precipitation
- Irkutsk in DecemberRussia · 522 kmHigh -11.4°C · Low -19.4°C · 9.5 mm precipitation
- Angarsk in DecemberRussia · 559 kmHigh -12.8°C · Low -21.5°C · 8.2 mm precipitation
- Usol’ye-Sibirskoye in DecemberRussia · 585 kmHigh -13.6°C · Low -22.1°C · 8.6 mm precipitation
- Chita in DecemberRussia · 659 kmHigh -15.6°C · Low -24.6°C · 3.4 mm precipitation
- Bayan Nur in DecemberChina · 798 kmHigh -1.7°C · Low -11.4°C · 1.0 mm precipitation
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.