Average Weather in April in Ilulissat Greenland
Daily high temperatures increase by 13°F, from 16°F to 29°F, rarely falling below 1°F or exceeding 40°F.
Daily low temperatures increase by 15°F, from 4°F to 19°F, rarely falling below -12°F or exceeding 30°F.
For reference, on July 18, the hottest day of the year, temperatures in Ilulissat typically range from 42°F to 52°F, while on February 27, the coldest day of the year, they range from -3°F to 8°F.
Average High and Low Temperature in April
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on April. 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.
Average Hourly Temperature in April
The month of April in Ilulissat experiences gradually decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 66% to 60%.
The clearest day of the month is April 30, with clear, mostly clear, or partly cloudy conditions 40% of the time.
For reference, on January 1, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 76%, while on July 10, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 51%.
Cloud Cover Categories in April
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Ilulissat, the chance of a wet day over the course of April is gradually increasing, starting the month at 9% and ending it at 12%.
For reference, the year's highest daily chance of a wet day is 23% on August 16, and its lowest chance is 6% on January 6.
Over the course of April in Ilulissat, the chance of a day with only rain increases from 1% to 3%, the chance of a day with mixed snow and rain remains an essentially constant 3% throughout, and the chance of a day with only snow remains an essentially constant 6% throughout.
Probability of Precipitation in April
To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during April in Ilulissat is gradually increasing, starting the month at 0.2 inches, when it rarely exceeds 0.9 inches or falls below -0.0 inches, and ending the month at 0.5 inches, when it rarely exceeds 1.3 inches or falls below -0.0 inches.
Average Monthly Rainfall in April
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. As with rainfall, we consider the liquid-equivalent snowfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day liquid-equivalent snowfall during April in Ilulissat is essentially constant, remaining about 0.4 inches throughout, and rarely exceeding 0.9 inches or falling below -0.0 inches.
The highest average 31-day liquid-equivalent accumulation is 0.4 inches on April 13.
Average Monthly Liquid-Equivalent Snowfall in April
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.
Neither polar day nor polar night occur during the month of April.
Over the course of April in Ilulissat, the length of the day is very rapidly increasing. From the start to the end of the month, the length of the day increases by 4 hours, 25 minutes, implying an average daily increase of 9 minutes, 8 seconds, and weekly increase of 1 hour, 3 minutes, 55 seconds.
The shortest day of the month is April 1, with 13 hours, 59 minutes of daylight and the longest day is April 30, with 18 hours, 24 minutes of daylight.
Hours of Daylight and Twilight in April
The latest sunrise of the month in Ilulissat is 6:29 AM on April 1 and the earliest sunrise is 2 hours, 18 minutes earlier at 4:11 AM on April 30.
The earliest sunset is 8:28 PM on April 1 and the latest sunset is 2 hours, 7 minutes later at 10:35 PM on April 30.
Daylight saving time is observed in Ilulissat during 2018, but it neither starts nor ends during April, so the entire month is in daylight saving time.
Sunrise & Sunset with Twilight and Daylight Saving Time in April
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 chance that a given day will be muggy in Ilulissat is essentially constant during April, remaining around 0% throughout.
Humidity Comfort Levels in April
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 is essentially constant during April, remaining within 0.2 miles per hour of 8.0 miles per hour throughout.
For reference, on November 29, the windiest day of the year, the daily average wind speed is 11.7 miles per hour, while on July 14, the calmest day of the year, the daily average wind speed is 5.5 miles per hour.
Average Wind Speed in April
Wind Direction in April
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 surface water temperature in Ilulissat is essentially constant during April, remaining around 30°F throughout.
Average Water Temperature in April
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.
The month of April in Ilulissat is reliably fully outside of the growing season.
Time Spent in Various Temperature Bands and the Growing Season in April
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 Ilulissat are essentially constant during April, remaining around 0°F throughout.
Growing Degree Days in April
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 in Ilulissat is rapidly increasing during April, rising by 1.8 kWh, from 2.7 kWh to 4.5 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in April
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 year round, 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.
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.