Average Weather in August in Helsinki Finland
In Helsinki, the month of August is characterized by falling daily high temperatures, with daily highs decreasing by 7°F, from 70°F to 63°F over the course of the month, and rarely exceeding 78°F or dropping below 56°F.
Daily low temperatures decrease by 6°F, from 55°F to 49°F, rarely falling below 41°F or exceeding 61°F.
For reference, on July 22, the hottest day of the year, temperatures in Helsinki typically range from 55°F to 71°F, while on February 7, the coldest day of the year, they range from 17°F to 27°F.
Average High and Low Temperature in August
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on August. 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 August
The month of August in Helsinki experiences gradually increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 43% to 50%.
The clearest day of the month is August 4, with clear, mostly clear, or partly cloudy conditions 57% of the time.
For reference, on January 23, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 75%, while on July 18, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 59%.
Cloud Cover Categories in August
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Helsinki, the chance of a wet day over the course of August is gradually increasing, starting the month at 25% and ending it at 29%.
For reference, the year's highest daily chance of a wet day is 32% on November 21, and its lowest chance is 17% on March 2.
Probability of Precipitation in August
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 August in Helsinki is essentially constant, remaining about 2.0 inches throughout, and rarely exceeding 4.2 inches or falling below 0.4 inches.
Average Monthly Rainfall in August
Over the course of August in Helsinki, the length of the day is very rapidly decreasing. From the start to the end of the month, the length of the day decreases by 2 hours, 37 minutes, implying an average daily decrease of 5 minutes, 14 seconds, and weekly decrease of 36 minutes, 38 seconds.
The shortest day of the month is August 31, with 14 hours, 15 minutes of daylight and the longest day is August 1, with 16 hours, 52 minutes of daylight.
Hours of Daylight and Twilight in August
The earliest sunrise of the month in Helsinki is 4:59 AM on August 1 and the latest sunrise is 1 hour, 12 minutes later at 6:12 AM on August 31.
The latest sunset is 9:51 PM on August 1 and the earliest sunset is 1 hour, 24 minutes earlier at 8:27 PM on August 31.
Daylight saving time is observed in Helsinki during 2017, but it neither starts nor ends during August, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 3:54 AM and sets 18 hours, 56 minutes later, at 10:50 PM, while on December 21, the shortest day of the year, it rises at 9:23 AM and sets 5 hours, 49 minutes later, at 3:12 PM.
Sunrise & Sunset with Twilight in August
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 Helsinki is gradually decreasing during August, falling from 3% to 0% over the course of the month.
For reference, on July 28, the muggiest day of the year, there are muggy conditions 3% of the time, while on January 1, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in August
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 Helsinki is gradually increasing during August, increasing from 4.0 miles per hour to 4.6 miles per hour over the course of the month.
For reference, on December 13, the windiest day of the year, the daily average wind speed is 6.1 miles per hour, while on July 3, the calmest day of the year, the daily average wind speed is 3.8 miles per hour.
Average Wind Speed in August
Wind Direction in August
Helsinki 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 Helsinki is gradually decreasing during August, falling by 2°F, from 63°F to 61°F, over the course of the month.
The highest average surface water temperature during August is 63°F on August 7.
Average Water Temperature in August
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 Helsinki is rapidly decreasing during August, falling by 1.7 kWh, from 5.4 kWh to 3.8 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in August
For the purposes of this report, the geographical coordinates of Helsinki are 60.170 deg latitude, 24.935 deg longitude, and 0 ft elevation.
The topography within 2 miles of Helsinki contains only modest variations in elevation, with a maximum elevation change of 148 feet and an average elevation above sea level of 36 feet. Within 10 miles also contains only modest variations in elevation (253 feet). Within 50 miles contains only modest variations in elevation (607 feet).
The area within 2 miles of Helsinki is covered by artificial surfaces (65%) and water (30%), within 10 miles by water (47%) and artificial surfaces (40%), and within 50 miles by water (49%) and trees (32%).
This report illustrates the typical weather in Helsinki 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 Helsinki.
For each station, the records are corrected for the elevation difference between that station and Helsinki 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 Helsinki is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Helsinki 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.