Average Weather in Attert Belgium
In Attert, the summers are comfortable and partly cloudy and the winters are very cold, windy, and mostly cloudy. Over the course of the year, the temperature typically varies from 31°F to 72°F and is rarely below 20°F or above 83°F.
Based on the tourism score, the best time of year to visit Attert for warm-weather activities is from late June to late August.
The warm season lasts for 3.1 months, from June 4 to September 8, with an average daily high temperature above 65°F. The hottest day of the year is August 5, with an average high of 72°F and low of 57°F.
The cold season lasts for 3.7 months, from November 17 to March 7, with an average daily high temperature below 45°F. The coldest day of the year is February 8, with an average low of 31°F and high of 39°F.
Average High and Low Temperature
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
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 Attert, 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 Attert begins around March 31 and lasts for 6.2 months, ending around October 6. On July 23, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 60% of the time, and overcast or mostly cloudy 40% of the time.
The cloudier part of the year begins around October 6 and lasts for 5.8 months, ending around March 31. On November 22, the cloudiest day of the year, the sky is overcast or mostly cloudy 79% of the time, and clear, mostly clear, or partly cloudy 21% of the time.
Cloud Cover Categories
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 Attert varies throughout the year.
The wetter season lasts 8.7 months, from May 9 to January 31, with a greater than 30% chance of a given day being a wet day. The chance of a wet day peaks at 36% on June 12.
The drier season lasts 3.3 months, from January 31 to May 9. The smallest chance of a wet day is 24% on March 3.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 36% on June 12.
Daily Chance of Precipitation
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. Attert experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year in Attert. The most rain falls during the 31 days centered around June 4, with an average total accumulation of 2.4 inches.
The least rain falls around March 6, with an average total accumulation of 1.7 inches.
Average Monthly Rainfall
The sliding 31-day liquid-equivalent quantity of snowfall in Attert does not vary significantly over the course of the year, staying within 0.1 inches of 0.1 inches throughout.
Average Liquid-Equivalent Monthly Snowfall
The length of the day in Attert varies extremely over the course of the year. In 2019, the shortest day is December 22, with 8 hours, 7 minutes of daylight; the longest day is June 21, with 16 hours, 20 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:28 AM on June 17, and the latest sunrise is 3 hours, 6 minutes later at 8:34 AM on January 1. The earliest sunset is at 4:36 PM on December 12, and the latest sunset is 5 hours, 13 minutes later at 9:48 PM on June 25.
Daylight saving time (DST) is observed in Attert during 2019, starting in the spring on March 31, lasting 6.9 months, and ending in the fall on October 27.
Sunrise & Sunset with Twilight and Daylight Saving Time
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 Attert, 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, remaining a virtually constant 0% throughout.
Humidity Comfort Levels
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 Attert experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 5.8 months, from October 15 to April 9, with average wind speeds of more than 9.9 miles per hour. The windiest day of the year is January 17, with an average hourly wind speed of 11.8 miles per hour.
The calmer time of year lasts for 6.2 months, from April 9 to October 15. The calmest day of the year is August 5, with an average hourly wind speed of 7.9 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Attert varies throughout the year.
The wind is most often from the west for 2.9 months, from January 20 to April 18; for 4.8 months, from May 6 to October 1; and for 1.1 weeks, from December 19 to December 27, with a peak percentage of 42% on July 7. The wind is most often from the east for 2.6 weeks, from April 18 to May 6, with a peak percentage of 28% on April 30. The wind is most often from the south for 2.6 months, from October 1 to December 19 and for 3.4 weeks, from December 27 to January 20, with a peak percentage of 39% on October 28.
Best Time of Year to Visit
To characterize how pleasant the weather is in Attert 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 Attert for general outdoor tourist activities is from late June to late August, with a peak score in the first week of August.
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 Attert for hot-weather activities is from mid July to mid August, with a peak score in the last week of July.
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 Attert typically lasts for 6.9 months (212 days), from around April 8 to around November 6, rarely starting before March 13 or after April 30, and rarely ending before October 16 or after December 3.
Time Spent in Various Temperature Bands and the Growing Season
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 Attert should appear around April 27, only rarely appearing before April 12 or after May 13.
Growing Degree Days
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 3.5 months, from May 3 to August 19, with an average daily incident shortwave energy per square meter above 5.4 kWh. The brightest day of the year is June 26, with an average of 6.5 kWh.
The darker period of the year lasts for 3.7 months, from October 27 to February 18, with an average daily incident shortwave energy per square meter below 1.8 kWh. The darkest day of the year is December 26, with an average of 0.7 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Attert are 49.750 deg latitude, 5.786 deg longitude, and 1,119 ft elevation.
The topography within 2 miles of Attert contains only modest variations in elevation, with a maximum elevation change of 430 feet and an average elevation above sea level of 1,086 feet. Within 10 miles contains only modest variations in elevation (1,047 feet). Within 50 miles contains very significant variations in elevation (2,044 feet).
The area within 2 miles of Attert is covered by cropland (44%), grassland (30%), and trees (22%), within 10 miles by trees (45%) and cropland (32%), and within 50 miles by trees (41%) and cropland (31%).
This report illustrates the typical weather in Attert, 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 Attert.
For each station, the records are corrected for the elevation difference between that station and Attert 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 Attert is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Attert and a given station.
The stations contributing to this reconstruction are: Luxembourg Findel Airport (62%, 34 kilometers, southeast) and Saint Hubert (38%, 42 kilometers, northwest).
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.