Average Weather in Ilulissat Greenland
In Ilulissat, the summers are cold; the winters are frigid, snowy, and windy; and it is mostly cloudy year round. Over the course of the year, the temperature typically varies from -3°F to 52°F and is rarely below -24°F or above 58°F.
The warm season lasts for 3.1 months, from June 3 to September 6, with an average daily high temperature above 43°F. The hottest day of the year is July 18, with an average high of 52°F and low of 42°F.
The cold season lasts for 3.2 months, from December 28 to April 3, with an average daily high temperature below 17°F. The coldest day of the year is February 27, with an average low of -3°F and high of 8°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
In Ilulissat, 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 in Ilulissat begins around April 21 and lasts for 6.4 months, ending around November 4. On July 10, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 51% of the time, and overcast or mostly cloudy 49% of the time.
The cloudier part of the year begins around November 4 and lasts for 5.6 months, ending around April 21. On January 1, the cloudiest day of the year, the sky is overcast or mostly cloudy 76% of the time, and clear, mostly clear, or partly cloudy 24% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Ilulissat varies throughout the year.
The wetter season lasts 5.3 months, from June 14 to November 23, with a greater than 14% chance of a given day being a wet day. The chance of a wet day peaks at 23% on August 16.
The drier season lasts 6.7 months, from November 23 to June 14. The smallest chance of a wet day is 6% on January 6.
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 Ilulissat changes throughout the year.
Snow alone is the most common for 6.3 months, from October 23 to May 4. The highest chance of a day with snow alone is 9% on November 29.
Rain alone is the most common for 5.7 months, from May 4 to October 23. The highest chance of a day with rain alone is 23% on August 16.
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. Ilulissat experiences some seasonal variation in monthly rainfall.
The rainy period of the year lasts for 6.5 months, from May 3 to November 17, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around August 16, with an average total accumulation of 1.8 inches.
The rainless period of the year lasts for 5.5 months, from November 17 to May 3. The least rain falls around January 8, with an average total accumulation of 0.1 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. Ilulissat experiences some seasonal variation in monthly liquid-equivalent snowfall.
The snowy period of the year lasts for 8.2 months, from September 22 to May 29, with a sliding 31-day liquid-equivalent snowfall of at least 0.1 inches. The most snow falls during the 31 days centered around November 19, with an average total liquid-equivalent accumulation of 0.5 inches.
The snowless period of the year lasts for 3.8 months, from May 29 to September 22. The least snow falls around July 29, with an average total liquid-equivalent accumulation of 0.0 inches.
Average Liquid-Equivalent Monthly Snowfall
Due to its extreme latitude, Ilulissat 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 in Ilulissat during 2017, the Sun is continuously above the horizon for 2.1 months, rising at 1:49 AM on May 19, and not setting again until 1:07 AM on July 24.
In the winter in Ilulissat during 2017, the Sun is continuously below the horizon for 1.5 months, setting at 12:24 PM on November 29, and not rising again until 12:14 PM on January 12.
Hours of Daylight and Twilight
Daylight saving time (DST) is observed in Ilulissat during 2017, starting in the spring on March 25, lasting 7.1 months, and ending in the fall on October 28.
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 in Ilulissat, 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 in Ilulissat experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 5.9 months, from September 19 to March 16, with average wind speeds of more than 4.6 miles per hour. The windiest day of the year is November 29, with an average hourly wind speed of 6.3 miles per hour.
The calmer time of year lasts for 6.1 months, from March 16 to September 19. The calmest day of the year is July 14, with an average hourly wind speed of 3.0 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Ilulissat varies throughout the year.
The wind is most often from the south for 5.0 months, from March 19 to August 18, with a peak percentage of 44% on July 29. The wind is most often from the east for 7.0 months, from August 18 to March 19, with a peak percentage of 47% on January 1.
Ilulissat 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 2.8 months, from July 3 to September 28, with an average temperature above 37°F. The day of the year with the warmest water is August 23, with an average temperature of 39°F.
The time of year with cooler water lasts for 5.0 months, from December 12 to May 11, with an average temperature below 32°F. The day of the year with the coolest water is March 9, 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 2.5 months, from May 11 to July 26, with an average daily incident shortwave energy per square meter above 5.2 kWh. The brightest day of the year is June 25, with an average of 6.5 kWh.
The darker period of the year lasts for 5.3 months, from October 1 to March 10, with an average daily incident shortwave energy per square meter below 1.3 kWh. The darkest day of the year is December 14, with an average of 0.0 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Ilulissat are 69.217 deg latitude, -51.100 deg longitude, and 0 ft elevation.
The topography within 2 miles of Ilulissat contains only modest variations in elevation, with a maximum elevation change of 394 feet and an average elevation above sea level of 101 feet. Within 10 miles contains only modest variations in elevation (1,654 feet). Within 50 miles contains very significant variations in elevation (4,396 feet).
The area within 2 miles of Ilulissat is covered by water (28%), sparse vegetation (25%), trees (17%), and snow and glaciers (16%), within 10 miles by water (50%) and snow and glaciers (21%), and within 50 miles by water (41%) and snow and glaciers (32%).
This report illustrates the typical weather in Ilulissat, 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, Egedesminde, in our network suitable to be used as a proxy for the historical temperature and dew point records of Ilulissat.
At a distance of 91 kilometers from Ilulissat, 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 Ilulissat 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 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.