Climate and Average Weather Year Round in Aland Islands Åland Islands
In Aland Islands, the summers are short, comfortable, and partly cloudy; the winters are long, freezing, snowy, and mostly cloudy; and it is windy year round. Over the course of the year, the temperature typically varies from 21°F to 68°F and is rarely below 3°F or above 76°F.
Based on the tourism score, the best time of year to visit Aland Islands for warm-weather activities is from early July to mid August.
Climate in Aland Islands
The warm season lasts for 2.8 months, from June 11 to September 6, with an average daily high temperature above 61°F. The hottest month of the year in Aland Islands is July, with an average high of 67°F and low of 53°F.
The cold season lasts for 4.0 months, from November 27 to March 27, with an average daily high temperature below 38°F. The coldest month of the year in Aland Islands is February, with an average low of 21°F and high of 31°F.
Average High and Low Temperature in Aland Islands
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, 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 Aland Islands
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
In Aland Islands, 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 Aland Islands begins around April 29 and lasts for 5.4 months, ending around October 10.
The clearest month of the year in Aland Islands is July, during which on average the sky is clear, mostly clear, or partly cloudy 58% of the time.
The cloudier part of the year begins around October 10 and lasts for 6.6 months, ending around April 29.
The cloudiest month of the year in Aland Islands is January, during which on average the sky is overcast or mostly cloudy 69% of the time.
Cloud Cover Categories in Aland Islands
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. The chance of wet days in Aland Islands varies throughout the year.
The wetter season lasts 5.5 months, from July 30 to January 13, with a greater than 24% chance of a given day being a wet day. The month with the most wet days in Aland Islands is November, with an average of 9.0 days with at least 0.04 inches of precipitation.
The drier season lasts 6.5 months, from January 13 to July 30. The month with the fewest wet days in Aland Islands is March, with an average of 5.2 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. The month with the most days of rain alone in Aland Islands is October, with an average of 8.3 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 29% on October 18.
Daily Chance of Precipitation in Aland Islands
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. Aland Islands experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year in Aland Islands. The month with the most rain in Aland Islands is August, with an average rainfall of 2.0 inches.
The month with the least rain in Aland Islands is February, with an average rainfall of 0.6 inches.
Average Monthly Rainfall in Aland Islands
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. Aland Islands experiences significant seasonal variation in monthly snowfall.
The snowy period of the year lasts for 5.2 months, from November 6 to April 13, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in Aland Islands is January, with an average snowfall of 4.0 inches.
The snowless period of the year lasts for 6.8 months, from April 13 to November 6. The least snow falls around July 29, with an average total accumulation of 0.0 inches.
Average Monthly Snowfall in Aland Islands
The length of the day in Aland Islands varies extremely over the course of the year. In 2021, the shortest day is December 21, with 5 hours, 47 minutes of daylight; the longest day is June 21, with 18 hours, 58 minutes of daylight.
Hours of Daylight and Twilight in Aland Islands
The earliest sunrise is at 4:12 AM on June 19, and the latest sunrise is 5 hours, 33 minutes later at 9:45 AM on December 26. The earliest sunset is at 3:30 PM on December 16, and the latest sunset is 7 hours, 40 minutes later at 11:10 PM on June 23.
Daylight saving time (DST) is observed in Aland Islands during 2021, starting in the spring on March 28, lasting 7.1 months, and ending in the fall on October 31.
Sunrise & Sunset with Twilight and Daylight Saving Time in Aland Islands
The figure below presents a compact representation of key lunar data for 2021. 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.
Moon Rise, Set & Phases in Aland Islands
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 Aland Islands, 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, staying within 1% of 1% throughout.
Humidity Comfort Levels in Aland Islands
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 Aland Islands experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 6.0 months, from September 17 to March 15, with average wind speeds of more than 14.5 miles per hour. The windiest month of the year in Aland Islands is December, with an average hourly wind speed of 17.5 miles per hour.
The calmer time of year lasts for 6.0 months, from March 15 to September 17. The calmest month of the year in Aland Islands is June, with an average hourly wind speed of 11.4 miles per hour.
Average Wind Speed in Aland Islands
The predominant average hourly wind direction in Aland Islands varies throughout the year.
The wind is most often from the south for 7.8 months, from February 25 to October 18, with a peak percentage of 41% on July 24. The wind is most often from the west for 4.2 months, from October 18 to February 25, with a peak percentage of 40% on January 1.
Wind Direction in Aland Islands
Aland Islands 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 significant seasonal variation over the course of the year.
The time of year with warmer water lasts for 2.4 months, from July 2 to September 15, with an average temperature above 56°F. The month of the year in Aland Islands with the warmest water is August, with an average temperature of 61°F.
The time of year with cooler water lasts for 4.6 months, from December 16 to May 5, with an average temperature below 39°F. The month of the year in Aland Islands with the coolest water is March, with an average temperature of 34°F.
Average Water Temperature in Aland Islands
To characterize how pleasant the weather is in Aland Islands 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 Aland Islands for general outdoor tourist activities is from early July to mid August, with a peak score in the third week of July.
Tourism Score in Aland Islands
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 Aland Islands for hot-weather activities is from mid July to early August, with a peak score in the last week of July.
Beach/Pool Score in Aland Islands
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 Aland Islands typically lasts for 4.5 months (138 days), from around May 17 to around October 2, rarely starting before April 29 or after June 4, and rarely ending before September 14 or after October 20.
Time Spent in Various Temperature Bands and the Growing Season in Aland Islands
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
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.
Based on growing degree days alone, the first spring blooms in Aland Islands should appear around June 2, only rarely appearing before May 22 or after June 16.
Growing Degree Days in Aland Islands
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 3.0 months, from May 8 to August 8, with an average daily incident shortwave energy per square meter above 5.3 kWh. The brightest month of the year in Aland Islands is June, with an average of 6.5 kWh.
The darker period of the year lasts for 4.4 months, from October 15 to February 27, with an average daily incident shortwave energy per square meter below 1.4 kWh. The darkest month of the year in Aland Islands is December, with an average of 0.2 kWh.
Average Daily Incident Shortwave Solar Energy in Aland Islands
For the purposes of this report, the geographical coordinates of Aland Islands are 60.250 deg latitude, 20.000 deg longitude, and 0 ft elevation.
The topography within 2 miles of Aland Islands is essentially flat, with a maximum elevation change of 0 feet and an average elevation above sea level of 0 feet. Within 10 miles is also essentially flat (0 feet). Within 50 miles is also essentially flat (0 feet).
The area within 2 miles of Aland Islands is covered by trees (59%), cropland (16%), and water (15%), within 10 miles by trees (54%) and water (27%), and within 50 miles by water (89%).
This report illustrates the typical weather in Aland Islands, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
The details of the data sources used for this report can be found on the Mariehamn Airport page.
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.