Average Weather in April in Reykjavík Iceland
In Reykjavík, the month of April is characterized by rising daily high temperatures, with daily highs increasing by 5°F, from 40°F to 45°F over the course of the month, and rarely exceeding 51°F or dropping below 32°F.
Daily low temperatures increase by 5°F, from 31°F to 36°F, rarely falling below 22°F or exceeding 43°F.
For reference, on July 31, the hottest day of the year, temperatures in Reykjavík typically range from 49°F to 57°F, while on January 24, the coldest day of the year, they range from 28°F to 36°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 Reykjavík experiences decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 68% to 59%.
The clearest day of the month is April 30, with clear, mostly clear, or partly cloudy conditions 41% of the time.
For reference, on January 21, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 78%, while on May 21, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 43%.
Cloud Cover in April
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Reykjavík, the chance of a wet day over the course of April is rapidly decreasing, starting the month at 44% and ending it at 37%.
For reference, the year's highest daily chance of a wet day is 55% on February 26, and its lowest chance is 29% on July 7.
Over the course of April in Reykjavík, the chance of a day with only rain remains an essentially constant 35% throughout, the chance of a day with mixed snow and rain decreases from 8% to 2%, and the chance of a day with only snow decreases from 4% to 0%.
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 Reykjavík is decreasing, starting the month at 3.3 inches, when it rarely exceeds 5.3 inches or falls below 1.5 inches, and ending the month at 2.7 inches, when it rarely exceeds 4.7 inches or falls below 1.0 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 Reykjavík is gradually decreasing, starting the month at 0.4 inches, when it rarely exceeds 0.9 inches, and ending the month at 0.1 inches, when it rarely exceeds 0.2 inches or falls below -0.0 inches.
Average Monthly Liquid-Equivalent Snowfall in April
Over the course of April in Reykjavík, 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 3 hours, 12 minutes, implying an average daily increase of 6 minutes, 37 seconds, and weekly increase of 46 minutes, 16 seconds.
The shortest day of the month is April 1, with 13 hours, 34 minutes of daylight and the longest day is April 30, with 16 hours, 46 minutes of daylight.
Hours of Daylight and Twilight in April
The latest sunrise of the month in Reykjavík is 6:45 AM on April 1 and the earliest sunrise is 1 hour, 42 minutes earlier at 5:02 AM on April 30.
The earliest sunset is 8:19 PM on April 1 and the latest sunset is 1 hour, 29 minutes later at 9:48 PM on April 30.
Daylight saving time is not observed in Reykjavík during 2017.
For reference, on June 21, the longest day of the year, the Sun rises at 2:55 AM and sets 21 hours, 9 minutes later, at 12:03 AM, while on December 21, the shortest day of the year, it rises at 11:22 AM and sets 4 hours, 7 minutes later, at 3:29 PM.
Sunrise & Sunset with Twilight 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 Reykjavík 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 Reykjavík is gradually decreasing during April, decreasing from 7.3 miles per hour to 6.3 miles per hour over the course of the month.
For reference, on January 7, the windiest day of the year, the daily average wind speed is 8.7 miles per hour, while on July 21, the calmest day of the year, the daily average wind speed is 4.3 miles per hour.
Average Wind Speed in April
Wind Direction in April
Reykjavík 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 Reykjavík is essentially constant during April, remaining within 1°F of 42°F throughout.
Average Water Temperature 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 Reykjavík is rapidly increasing during April, rising by 1.6 kWh, from 2.3 kWh to 3.9 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 Reykjavík are 64.135 deg latitude, -21.895 deg longitude, and 3 ft elevation.
The topography within 2 miles of Reykjavík contains only modest variations in elevation, with a maximum elevation change of 203 feet and an average elevation above sea level of 57 feet. Within 10 miles contains only modest variations in elevation (2,851 feet). Within 50 miles contains large variations in elevation (4,426 feet).
The area within 2 miles of Reykjavík is covered by artificial surfaces (83%), within 10 miles by water (39%) and shrubs (30%), and within 50 miles by water (53%) and shrubs (23%).
This report illustrates the typical weather in Reykjavík 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 are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Reykjavík.
For each station, the records are corrected for the elevation difference between that station and Reykjavík according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Reykjavík is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Reykjavík and a given station.
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.