Climate and Average Weather Year Round 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.

Based on the tourism score, the best time of year to visit Ilulissat for warm-weather activities is for the entire month of July.

The warm season lasts for 3.0 months, from June 4 to September 5, with an average daily high temperature above 43°F. The hottest month of the year in Ilulissat is July, with an average high of 51°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 month of the year in Ilulissat is February, with an average low of -2°F and high of 9°F.

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 22 and lasts for 6.4 months, ending around November 3.

The clearest month of the year in Ilulissat is June, during which on average the sky is clear, mostly clear, or partly cloudy 49% of the time.

The cloudier part of the year begins around November 3 and lasts for 5.6 months, ending around April 22.

The cloudiest month of the year in Ilulissat is January, during which on average the sky is overcast or mostly cloudy 74% 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 in Ilulissat varies throughout the year.

The wetter season lasts 5.3 months, from June 13 to November 23, with a greater than 14% chance of a given day being a wet day. The month with the most wet days in Ilulissat is August, with an average of 6.6 days with at least 0.04 inches of precipitation.

The drier season lasts 6.7 months, from November 23 to June 13. The month with the fewest wet days in Ilulissat is January, with an average of 2.0 days with at least 0.04 inches of precipitation.

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 month with the most days of snow alone in Ilulissat is November, with an average of 2.4 days.

Rain alone is the most common for 5.7 months, from May 4 to October 23. The month with the most days of rain alone in Ilulissat is August, with an average of 6.6 days.

Rainfall

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 month with the most rain in Ilulissat is August, with an average rainfall of 1.8 inches.

The rainless period of the year lasts for 5.5 months, from November 17 to May 3. The month with the least rain in Ilulissat is January, with an average rainfall of 0.1 inches.

Snowfall

As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Ilulissat experiences significant seasonal variation in monthly snowfall.

The snowy period of the year lasts for 8.2 months, from September 22 to May 29, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Ilulissat is November, with an average snowfall of 5.2 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 accumulation of 0.0 inches.

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 2026, the Sun is continuously above the horizon for 2.1 months, rising at 2:52 AM on May 19, and not setting again until 2:13 AM on July 24.

In the winter in Ilulissat during 2026, the Sun is continuously below the horizon for 1.5 months, setting at 1:29 PM on November 29, and not rising again until 1:20 PM on January 12.

Daylight saving time (DST) is observed in Ilulissat during 2026, starting in the spring on March 29, lasting 6.9 months, and ending in the fall on October 24.

The figure below presents a compact representation of key lunar data for 2026. 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.

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.

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 20 to March 15, with average wind speeds of more than 8.6 miles per hour. The windiest month of the year in Ilulissat is December, with an average hourly wind speed of 11.5 miles per hour.

The calmer time of year lasts for 6.1 months, from March 15 to September 20. The calmest month of the year in Ilulissat is July, with an average hourly wind speed of 5.7 miles per hour.

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 43% 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 27, with an average temperature above 37°F. The month of the year in Ilulissat with the warmest water is August, with an average temperature of 38°F.

The time of year with cooler water lasts for 5.0 months, from December 12 to May 10, with an average temperature below 32°F. The month of the year in Ilulissat with the coolest water is March, with an average temperature of 30°F.

To characterize how pleasant the weather is in Ilulissat 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 Ilulissat for general outdoor tourist activities is for the entire month of July, with a peak score in the third week of July.

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 Ilulissat for hot-weather activities is from early to mid July.

Methodology

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 Ilulissat typically lasts for 3.0 months (92 days), from around June 8 to around September 8, rarely starting before May 19 or after July 2, and rarely ending before August 18 or after September 26.

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.

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 12 to July 26, with an average daily incident shortwave energy per square meter above 5.2 kWh. The brightest month of the year in Ilulissat is June, with an average of 6.4 kWh.

The darker period of the year lasts for 5.2 months, from October 2 to March 9, with an average daily incident shortwave energy per square meter below 1.3 kWh. The darkest month of the year in Ilulissat is December, with an average of 0.0 kWh.

For the purposes of this report, the geographical coordinates of Ilulissat are 69.217 deg latitude, -51.100 deg longitude, and 115 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%).