December Weather in Ulan Bator MongoliaDaily high temperatures decrease by 9°F, from 11°F to 2°F, rarely falling below -9°F or exceeding 23°F. Daily low temperatures decrease by 8°F, from -9°F to -17°F, rarely falling below -28°F or exceeding 3°F. For reference, on July 14, the hottest day of the year, temperatures in Ulan Bator typically range from 54°F to 75°F, while on January 18, the coldest day of the year, they range from -19°F to 2°F. The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on December. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day. High Level, Canada (4,676 miles away) and Flin Flon, Canada (5,154 miles) are the far-away foreign places with temperatures most similar to Ulan Bator (view comparison). CloudsThe month of December in Ulan Bator experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 45% throughout the month. The highest chance of overcast or mostly cloudy conditions is 46% on December 16. The clearest day of the month is December 30, with clear, mostly clear, or partly cloudy conditions 57% of the time. For reference, on June 23, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 49%, while on October 2, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 62%. PrecipitationA wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Ulan Bator, the chance of a wet day over the course of December is essentially constant, remaining around 1% throughout. For reference, the year's highest daily chance of a wet day is 33% on July 21, and its lowest chance is 0% on January 30. SunOver the course of December in Ulan Bator, the length of the day is essentially constant. The shortest day of the month is December 21, with 8 hours, 23 minutes of daylight and the longest day is December 1, with 8 hours, 41 minutes of daylight. The earliest sunrise of the month in Ulan Bator is 8:20 AM on December 1 and the latest sunrise is 21 minutes later at 8:41 AM on December 31. The earliest sunset is 4:59 PM on December 10 and the latest sunset is 10 minutes later at 5:09 PM on December 31. Daylight saving time is not observed in Ulan Bator during 2024. For reference, on June 20, the longest day of the year, the Sun rises at 4:53 AM and sets 16 hours, 2 minutes later, at 8:55 PM, while on December 21, the shortest day of the year, it rises at 8:39 AM and sets 8 hours, 23 minutes later, at 5:02 PM. The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation. MoonThe figure below presents a compact representation of key lunar data for December 2024. 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. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
HumidityWe 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 chance that a given day will be muggy in Ulan Bator is essentially constant during December, remaining around 0% throughout. For reference, on July 30, the muggiest day of the year, there are muggy conditions 0% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time. WindThis 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 is gradually decreasing during December, decreasing from 8.5 miles per hour to 7.9 miles per hour over the course of the month. For reference, on May 3, the windiest day of the year, the daily average wind speed is 11.9 miles per hour, while on January 8, the calmest day of the year, the daily average wind speed is 7.9 miles per hour. The wind direction in Ulan Bator during December is predominantly out of the west from December 1 to December 25 and the north from December 25 to December 31. Growing SeasonDefinitions 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 25 to around September 9, rarely starting before May 6 or after June 13, and rarely ending before August 24 or after September 26. The month of December in Ulan Bator is reliably fully outside of the growing season. 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. The average accumulated growing degree days in Ulan Bator are essentially constant during December, remaining around 1,524°F throughout. Solar EnergyThis 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 in Ulan Bator is essentially constant during December, remaining within 0.1 kWh of 1.5 kWh throughout. The lowest average daily incident shortwave solar energy during December is 1.4 kWh on December 21. TopographyFor 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%). Data SourcesThis 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 PointThere 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. Other DataAll 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 © OpenStreetMap contributors. DisclaimerThe 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. Please review our full terms contained on our Terms of Service page. |