Climate and Average Weather Year Round in Ulan Bator Mongolia
In Ulan Bator, the summers are long and comfortable, the winters are frigid and dry, and it is partly cloudy year round. Over the course of the year, the temperature typically varies from -19°F to 75°F and is rarely below -31°F or above 87°F.
Based on the tourism score, the best time of year to visit Ulan Bator for warm-weather activities is from early July to mid August.
Climate in Ulan Bator
Average Temperature in Ulan Bator
The warm season lasts for 4.0 months, from May 14 to September 16, with an average daily high temperature above 61°F. The hottest day of the year is July 15, with an average high of 75°F and low of 54°F.
The cold season lasts for 3.0 months, from November 23 to February 22, with an average daily high temperature below 16°F. The coldest day of the year is January 18, with an average low of -19°F and high of 2°F.
Average High and Low Temperature in Ulan Bator
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in Ulan Bator
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
In Ulan Bator, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.
The clearer part of the year in Ulan Bator begins around August 20 and lasts for 3.3 months, ending around November 28. On October 3, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 62% of the time, and overcast or mostly cloudy 38% of the time.
The cloudier part of the year begins around November 28 and lasts for 8.7 months, ending around August 20. On June 24, the cloudiest day of the year, the sky is overcast or mostly cloudy 49% of the time, and clear, mostly clear, or partly cloudy 51% of the time.
Cloud Cover Categories in Ulan Bator
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Ulan Bator varies significantly throughout the year.
The wetter season lasts 3.3 months, from June 1 to September 9, with a greater than 16% chance of a given day being a wet day. The chance of a wet day peaks at 33% on July 21.
The drier season lasts 8.7 months, from September 9 to June 1. The smallest chance of a wet day is 0% on January 29.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation in Ulan Bator changes throughout the year.
Rain alone is the most common for 6.7 months, from April 3 to October 24. The highest chance of a day with rain alone is 33% on July 21.
Snow alone is the most common for 5.3 months, from October 24 to April 3. The highest chance of a day with snow alone is 2% on November 4.
Daily Chance of Precipitation in Ulan Bator
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Ulan Bator experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 4.5 months, from May 10 to September 25, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around July 30, with an average total accumulation of 2.1 inches.
The rainless period of the year lasts for 7.5 months, from September 25 to May 10. The least rain falls around December 16, with an average total accumulation of 0.0 inches.
Average Monthly Rainfall in Ulan Bator
The length of the day in Ulan Bator varies extremely over the course of the year. In 2021, the shortest day is December 21, with 8 hours, 23 minutes of daylight; the longest day is June 21, with 16 hours, 2 minutes of daylight.
Hours of Daylight and Twilight in Ulan Bator
The earliest sunrise is at 4:52 AM on June 16, and the latest sunrise is 3 hours, 49 minutes later at 8:41 AM on January 1. The earliest sunset is at 4:59 PM on December 11, and the latest sunset is 3 hours, 56 minutes later at 8:55 PM on June 26.
Daylight saving time (DST) is not observed in Ulan Bator during 2021.
Sunrise & Sunset with Twilight in Ulan Bator
The figure below presents a compact representation of key lunar data for 2021. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.
Moon Rise, Set & Phases in Ulan Bator
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The perceived humidity level in Ulan Bator, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
Humidity Comfort Levels in Ulan Bator
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Ulan Bator experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 3.0 months, from March 11 to June 12, with average wind speeds of more than 9.9 miles per hour. The windiest day of the year is May 4, with an average hourly wind speed of 11.9 miles per hour.
The calmer time of year lasts for 9.0 months, from June 12 to March 11. The calmest day of the year is January 8, with an average hourly wind speed of 7.9 miles per hour.
Average Wind Speed in Ulan Bator
The predominant average hourly wind direction in Ulan Bator varies throughout the year.
The wind is most often from the west for 2.0 months, from October 26 to December 26, with a peak percentage of 39% on November 30. The wind is most often from the north for 10 months, from December 26 to October 26, with a peak percentage of 35% on January 1.
Wind Direction in Ulan Bator
Best Time of Year to Visit
To characterize how pleasant the weather is in Ulan Bator throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit Ulan Bator for general outdoor tourist activities is from early July to mid August, with a peak score in the last week of July.
Tourism Score in Ulan Bator
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit Ulan Bator for hot-weather activities is from early July to early August, with a peak score in the third week of July.
Beach/Pool Score in Ulan Bator
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
The growing season in Ulan Bator typically lasts for 3.5 months (107 days), from around May 26 to around September 10, rarely starting before May 7 or after June 14, and rarely ending before August 25 or after September 27.
Time Spent in Various Temperature Bands and the Growing Season in Ulan Bator
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
Based on growing degree days alone, the first spring blooms in Ulan Bator should appear around May 13, only rarely appearing before May 5 or after May 21.
Growing Degree Days in Ulan Bator
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.6 months, from April 22 to August 9, with an average daily incident shortwave energy per square meter above 6.0 kWh. The brightest day of the year is June 5, with an average of 7.1 kWh.
The darker period of the year lasts for 3.2 months, from November 2 to February 7, with an average daily incident shortwave energy per square meter below 2.6 kWh. The darkest day of the year is December 22, with an average of 1.4 kWh.
Average Daily Incident Shortwave Solar Energy in Ulan Bator
For the purposes of this report, the geographical coordinates of Ulan Bator are 47.908 deg latitude, 106.883 deg longitude, and 4,213 ft elevation.
The topography within 2 miles of Ulan Bator contains significant variations in elevation, with a maximum elevation change of 636 feet and an average elevation above sea level of 4,268 feet. Within 10 miles contains significant variations in elevation (3,340 feet). Within 50 miles also contains extreme variations in elevation (5,912 feet).
The area within 2 miles of Ulan Bator is covered by artificial surfaces (84%), within 10 miles by sparse vegetation (30%) and artificial surfaces (18%), and within 50 miles by sparse vegetation (54%) and grassland (23%).
This report illustrates the typical weather in Ulan Bator, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There is only a single weather station, Ulan-Bator Chinggis Khan International Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of Ulan Bator.
At a distance of 11 kilometers from Ulan Bator, closer than our threshold of 150 kilometers, this station is deemed sufficiently nearby to be relied upon as our primary source for temperature and dew point records.
The station records are corrected for the elevation difference between the station and Ulan Bator according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
Please note that the station records themselves may additionally have been back-filled using other nearby stations or the MERRA-2 reanalysis.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for airports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.