Average Weather at Thule Air Base Greenland
At Thule Air Base, the summers are chilly and partly cloudy and the winters are long, frigid, dry, windy, and mostly cloudy. Over the course of the year, the temperature typically varies from -19°F to 46°F and is rarely below -32°F or above 54°F.
The warm season lasts for 3.2 months, from June 2 to September 9, with an average daily high temperature above 35°F. The hottest day of the year is July 19, with an average high of 46°F and low of 39°F.
The cold season lasts for 4.0 months, from December 5 to April 6, with an average daily high temperature below 3°F. The coldest day of the year is February 24, with an average low of -19°F and high of -7°F.
Average High and Low Temperature
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
At Thule Air Base, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year at Thule Air Base begins around April 13 and lasts for 5.8 months, ending around October 8. On June 3, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 54% of the time, and overcast or mostly cloudy 46% of the time.
The cloudier part of the year begins around October 8 and lasts for 6.2 months, ending around April 13. On February 25, the cloudiest day of the year, the sky is overcast or mostly cloudy 73% of the time, and clear, mostly clear, or partly cloudy 27% of the time.
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days at Thule Air Base varies throughout the year.
The wetter season lasts 3.9 months, from June 23 to October 20, with a greater than 13% chance of a given day being a wet day. The chance of a wet day peaks at 25% on August 4.
The drier season lasts 8.1 months, from October 20 to June 23. The smallest chance of a wet day is 1% on March 24.
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 at Thule Air Base changes throughout the year.
Snow alone is the most common for 8.0 months, from September 22 to May 23. The highest chance of a day with snow alone is 11% on October 20.
Rain alone is the most common for 4.0 months, from May 23 to September 22. The highest chance of a day with rain alone is 24% on August 4.
Daily Chance of Precipitation
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. Thule Air Base experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 3.3 months, from June 9 to September 18, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around August 2, with an average total accumulation of 1.8 inches.
The rainless period of the year lasts for 8.7 months, from September 18 to June 9. The least rain falls around February 26, with an average total accumulation of 0.0 inches.
Average Monthly Rainfall
We report snowfall in liquid-equivalent terms. The actual depth of new snowfall is typically between 5 and 10 times the liquid-equivalent amount, assuming the ground is frozen. Colder, drier snow tends to be on the higher end of that range and warmer, wetter snow on the lower end.
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Thule Air Base experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 9.5 months, from August 22 to June 6, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around October 11, with an average total liquid-equivalent accumulation of 0.6 inches.
The snowless period of the year lasts for 2.5 months, from June 6 to August 22. The least snow falls around July 23, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
Due to its extreme latitude, Thule Air Base experiences polar day (also known as the midnight Sun) during the summer and polar night during the winter. These are periods of time in which the sun is continuously above or below the horizon for more than one day. The precise start and end dates of polar day and night vary from year to year and depend on the precise location and elevation of the observer, and the local topography.
In the summer at Thule Air Base during 2017, the Sun is continuously above the horizon for 3.9 months, rising at 1:50 AM on April 23, and not setting again until 12:54 AM on August 20.
In the winter at Thule Air Base during 2017, the Sun is continuously below the horizon for 3.4 months, setting at 2:07 PM on October 30, and not rising again until 12:13 PM on February 10.
Hours of Daylight and Twilight
Daylight saving time (DST) is observed at Thule Air Base during 2017, starting in the spring on March 12, lasting 7.8 months, and ending in the fall on November 5.
Sunrise & Sunset with Twilight and Daylight Saving Time
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 at Thule Air Base, 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
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 at Thule Air Base experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 4.3 months, from July 10 to November 19, with average wind speeds of more than 5.2 miles per hour. The windiest day of the year is August 4, with an average hourly wind speed of 5.8 miles per hour.
The calmer time of year lasts for 7.7 months, from November 19 to July 10. The calmest day of the year is April 18, with an average hourly wind speed of 4.6 miles per hour.
Average Wind Speed
The predominant average hourly wind direction at Thule Air Base is from the east throughout the year.
Thule Air Base is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences some seasonal variation over the course of the year.
The time of year with warmer water lasts for 1.6 months, from July 15 to September 4, with an average temperature above 35°F. The day of the year with the warmest water is August 9, with an average temperature of 36°F.
The time of year with cooler water lasts for 7.4 months, from October 20 to June 3, with an average temperature below 31°F. The day of the year with the coolest water is March 24, with an average temperature of 30°F.
Average Water Temperature
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 2.3 months, from May 13 to July 22, with an average daily incident shortwave energy per square meter above 5.5 kWh. The brightest day of the year is June 19, with an average of 7.0 kWh.
The darker period of the year lasts for 6.2 months, from September 18 to March 25, with an average daily incident shortwave energy per square meter below 1.5 kWh. The darkest day of the year is November 15, with an average of 0.0 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Thule Air Base are 76.531 deg latitude, -68.702 deg longitude, and 377 ft elevation.
The topography within 2 miles of Thule Air Base contains significant variations in elevation, with a maximum elevation change of 725 feet and an average elevation above sea level of 396 feet. Within 10 miles contains significant variations in elevation (2,657 feet). Within 50 miles contains large variations in elevation (4,446 feet).
The area within 2 miles of Thule Air Base is covered by sparse vegetation (99%), within 10 miles by sparse vegetation (50%) and water (36%), and within 50 miles by snow and glaciers (49%) and water (40%).
This report illustrates the typical weather at Thule Air Base, 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
Thule Air Base has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.There are no other weather stations in our network within 200 kilometers of this location. Consequently, in the case of missing or erroneous measurements from this station, we fall back on NASA's MERRA-2 modern-era reanalysis , adjusted according to typical seasonal and diurnal differences between this station and the wide-area MERRA-2 reconstructed values.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , 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 aiports 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.