September Weather at Saint-Hubert Air Base Belgium
Daily high temperatures decrease by 6°F, from 64°F to 58°F, rarely falling below 49°F or exceeding 74°F.
Daily low temperatures decrease by 5°F, from 51°F to 47°F, rarely falling below 40°F or exceeding 59°F.
For reference, on August 4, the hottest day of the year, temperatures at Saint-Hubert Air Base typically range from 54°F to 69°F, while on February 8, the coldest day of the year, they range from 29°F to 37°F.
Average High and Low Temperature in September at Saint-Hubert Air Base
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on September. 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 September at Saint-Hubert Air Base
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 September at Saint-Hubert Air Base experiences increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 47% to 58%.
The clearest day of the month is September 1, with clear, mostly clear, or partly cloudy conditions 53% of the time.
For reference, on November 22, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 79%, while on July 23, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 58%.
Cloud Cover Categories in September at Saint-Hubert Air Base
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. At Saint-Hubert Air Base, the chance of a wet day over the course of September is essentially constant, remaining around 29% throughout.
For reference, the year's highest daily chance of a wet day is 37% on December 22, and its lowest chance is 26% on April 17.
Probability of Precipitation in September at Saint-Hubert Air Base
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 September at Saint-Hubert Air Base is essentially constant, remaining about 2.3 inches throughout, and rarely exceeding 4.1 inches or falling below 0.8 inches.
Average Monthly Rainfall in September at Saint-Hubert Air Base
Over the course of September at Saint-Hubert Air Base, the length of the day is rapidly decreasing. From the start to the end of the month, the length of the day decreases by 1 hour, 47 minutes, implying an average daily decrease of 3 minutes, 41 seconds, and weekly decrease of 25 minutes, 49 seconds.
The shortest day of the month is September 30, with 11 hours, 42 minutes of daylight and the longest day is September 1, with 13 hours, 29 minutes of daylight.
Hours of Daylight and Twilight in September at Saint-Hubert Air Base
The earliest sunrise of the month at Saint-Hubert Air Base is 6:53 AM on September 1 and the latest sunrise is 44 minutes later at 7:36 AM on September 30.
The latest sunset is 8:22 PM on September 1 and the earliest sunset is 1 hour, 3 minutes earlier at 7:18 PM on September 30.
Daylight saving time is observed at Saint-Hubert Air Base during 2021, but it neither starts nor ends during September, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:28 AM and sets 16 hours, 23 minutes later, at 9:51 PM, while on December 21, the shortest day of the year, it rises at 8:34 AM and sets 8 hours, 4 minutes later, at 4:38 PM.
Sunrise & Sunset with Twilight and Daylight Saving Time in September at Saint-Hubert Air Base
The figure below presents a compact representation of key lunar data for September 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. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
Moon Rise, Set & Phases in September at Saint-Hubert Air Base
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 at Saint-Hubert Air Base is essentially constant during September, remaining around 0% throughout.
For reference, on July 13, the muggiest day of the year, there are muggy conditions 0% 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 September at Saint-Hubert Air Base
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 at Saint-Hubert Air Base is essentially constant during September, remaining within 0.2 miles per hour of 9.3 miles per hour throughout.
For reference, on January 17, the windiest day of the year, the daily average wind speed is 12.5 miles per hour, while on August 5, the calmest day of the year, the daily average wind speed is 8.1 miles per hour.
Average Wind Speed in September at Saint-Hubert Air Base
The wind direction at Saint-Hubert Air Base during September is predominantly out of the west from September 1 to September 20 and the south from September 20 to September 30.
Wind Direction in September at Saint-Hubert Air Base
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 at Saint-Hubert Air Base typically lasts for 6.4 months (197 days), from around April 20 to around November 2, rarely starting before March 31 or after May 10, and rarely ending before October 12 or after November 30.
The month of September at Saint-Hubert Air Base is reliably fully within the growing season.
Time Spent in Various Temperature Bands and the Growing Season in September at Saint-Hubert Air Base
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.
The average accumulated growing degree days at Saint-Hubert Air Base are gradually increasing during September, increasing by 165°F, from 1,119°F to 1,283°F, over the course of the month.
Growing Degree Days in September at Saint-Hubert Air Base
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 at Saint-Hubert Air Base is rapidly decreasing during September, falling by 1.6 kWh, from 4.7 kWh to 3.1 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in September at Saint-Hubert Air Base
For the purposes of this report, the geographical coordinates of Saint-Hubert Air Base are 50.034 deg latitude, 5.440 deg longitude, and 1,916 ft elevation.
The topography within 2 miles of Saint-Hubert Air Base contains significant variations in elevation, with a maximum elevation change of 528 feet and an average elevation above sea level of 1,759 feet. Within 10 miles contains significant variations in elevation (1,306 feet). Within 50 miles contains very significant variations in elevation (2,234 feet).
The area within 2 miles of Saint-Hubert Air Base is covered by trees (94%), within 10 miles by trees (57%) and cropland (24%), and within 50 miles by trees (39%) and cropland (30%).
This report illustrates the typical weather at Saint-Hubert Air Base, 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
Saint-Hubert Air Base has a weather station that reported reliably enough during the analysis period that we have included it in our network. When available, historical temperature and dew point measurements are taken directly from this weather station. These records are obtained from NOAA's Integrated Surface Hourly data set, falling back on ICAO METAR records as required.
In the case of missing or erroneous measurements from this station, we fall back on records from nearby stations, adjusted according to typical seasonal and diurnal intra-station differences. For a given day of the year and hour of the day, the fallback station is selected to minimize the prediction error over the years for which there are measurements for both stations.
The stations on which we may fall back include but are not limited to Saint Hubert, Liege, Liège Airport, Spa-La Sauvenière Airport, Sint-Truiden, Florennes Air Base, Charleville-Mézières, and Elsenborn-Butgenbach Air Base.
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 airports 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.