Average Weather in April in Oulu Finland
Daily high temperatures increase by 12°F, from 36°F to 47°F, rarely falling below 28°F or exceeding 58°F.
Daily low temperatures increase by 10°F, from 22°F to 32°F, rarely falling below 8°F or exceeding 39°F.
For reference, on July 22, the hottest day of the year, temperatures in Oulu typically range from 54°F to 69°F, while on February 3, the coldest day of the year, they range from 7°F to 20°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
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The month of April in Oulu 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 28, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 82%, while on June 29, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 52%.
Cloud Cover Categories in April
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Oulu, the chance of a wet day over the course of April is increasing, starting the month at 18% and ending it at 22%.
For reference, the year's highest daily chance of a wet day is 33% on July 28, and its lowest chance is 17% on March 29.
Over the course of April in Oulu, the chance of a day with only rain increases from 9% to 20%, the chance of a day with mixed snow and rain decreases from 5% to 2%, and the chance of a day with only snow decreases from 4% to 1%.
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 Oulu is increasing, starting the month at 0.6 inches, when it rarely exceeds 1.1 inches or falls below 0.2 inches, and ending the month at 1.3 inches, when it rarely exceeds 2.3 inches or falls below 0.5 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 Oulu is gradually decreasing, starting the month at 0.4 inches, when it rarely exceeds 0.7 inches, and ending the month at 0.1 inches, when it rarely exceeds 0.2 inches.
Average Monthly Liquid-Equivalent Snowfall in April
Over the course of April in Oulu, 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, 21 minutes, implying an average daily increase of 6 minutes, 57 seconds, and weekly increase of 48 minutes, 37 seconds.
The shortest day of the month is April 1, with 13 hours, 39 minutes of daylight and the longest day is April 30, with 17 hours, 0 minutes of daylight.
Hours of Daylight and Twilight in April
The latest sunrise of the month in Oulu is 6:33 AM on April 1 and the earliest sunrise is 1 hour, 47 minutes earlier at 4:46 AM on April 30.
The earliest sunset is 8:12 PM on April 1 and the latest sunset is 1 hour, 34 minutes later at 9:46 PM on April 30.
Daylight saving time is observed in Oulu during 2020, but it neither starts nor ends during April, so the entire month is in daylight saving time.
For reference, on June 20, the longest day of the year, the Sun rises at 2:18 AM and sets 22 hours, 3 minutes later, at 12:21 AM, while on December 21, the shortest day of the year, it rises at 10:29 AM and sets 3 hours, 34 minutes later, at 2:03 PM.
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 Oulu is essentially constant during April, remaining around 0% throughout.
For reference, on July 27, the muggiest day of the year, there are muggy conditions 2% of the time, while on September 12, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in April
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
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 Oulu is gradually decreasing during April, decreasing from 7.1 miles per hour to 6.4 miles per hour over the course of the month.
For reference, on January 25, the windiest day of the year, the daily average wind speed is 8.5 miles per hour, while on July 22, the calmest day of the year, the daily average wind speed is 5.3 miles per hour.
Average Wind Speed in April
The wind direction in Oulu during April is predominantly out of the south from April 1 to April 25 and the west from April 25 to April 30.
Wind Direction in April
Oulu 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 Oulu is gradually increasing during April, rising by 2°F, from 31°F to 33°F, over the course of the month.
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 Oulu typically lasts for 4.2 months (129 days), from around May 13 to around September 19, rarely starting before April 25 or after May 31, and rarely ending before August 31 or after October 8.
The month of April in Oulu is more likely than not fully outside of the growing season, with the chance that a given day is in the growing season increasing from 0% to 18% over the course of the month.
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 Oulu are essentially constant during April, remaining within 4°F of 4°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 Oulu is rapidly increasing during April, rising by 1.5 kWh, from 2.8 kWh to 4.3 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 Oulu are 65.012 deg latitude, 25.468 deg longitude, and 23 ft elevation.
The topography within 2 miles of Oulu is essentially flat, with a maximum elevation change of 69 feet and an average elevation above sea level of 24 feet. Within 10 miles is essentially flat (200 feet). Within 50 miles contains only modest variations in elevation (623 feet).
The area within 2 miles of Oulu is covered by artificial surfaces (83%) and trees (11%), within 10 miles by trees (48%) and water (26%), and within 50 miles by trees (51%) and water (31%).
This report illustrates the typical weather in Oulu 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, Oulu Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of Oulu.
At a distance of 11 kilometers from Oulu, 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 Oulu 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 Algorithms 2nd Edition , 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.