Average Weather in September in Grande Cache Canada
Daily high temperatures decrease by 9°F, from 64°F to 55°F, rarely falling below 43°F or exceeding 76°F.
Daily low temperatures decrease by 7°F, from 38°F to 31°F, rarely falling below 22°F or exceeding 45°F.
For reference, on August 5, the hottest day of the year, temperatures in Grande Cache typically range from 42°F to 70°F, while on December 29, the coldest day of the year, they range from 5°F to 26°F.
Average High and Low Temperature in September
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
The month of September in Grande Cache experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 53% throughout the month.
The clearest day of the month is September 1, with clear, mostly clear, or partly cloudy conditions 48% of the time.
For reference, on February 25, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 68%, while on August 3, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 56%.
Cloud Cover Categories in September
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Grande Cache, the chance of a wet day over the course of September is very rapidly decreasing, starting the month at 26% and ending it at 18%.
For reference, the year's highest daily chance of a wet day is 42% on June 22, and its lowest chance is 8% on February 15.
Over the course of September in Grande Cache, the chance of a day with only rain decreases from 26% to 13%, the chance of a day with mixed snow and rain increases from 1% to 3%, and the chance of a day with only snow remains an essentially constant 1% throughout.
Probability of Precipitation in September
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 in Grande Cache is decreasing, starting the month at 1.7 inches, when it rarely exceeds 2.9 inches or falls below 0.7 inches, and ending the month at 0.9 inches, when it rarely exceeds 1.6 inches or falls below 0.4 inches.
Average Monthly Rainfall in September
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 September in Grande Cache is essentially constant, remaining about 0.1 inches throughout, and rarely exceeding 0.4 inches or falling below -0.0 inches.
Average Monthly Liquid-Equivalent Snowfall in September
Over the course of September in Grande Cache, 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, 3 minutes, implying an average daily decrease of 4 minutes, 15 seconds, and weekly decrease of 29 minutes, 43 seconds.
The shortest day of the month is September 30, with 11 hours, 38 minutes of daylight and the longest day is September 1, with 13 hours, 41 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in Grande Cache is 7:05 AM on September 1 and the latest sunrise is 52 minutes later at 7:56 AM on September 30.
The latest sunset is 8:46 PM on September 1 and the earliest sunset is 1 hour, 11 minutes earlier at 7:34 PM on September 30.
Daylight saving time is observed in Grande Cache during 2018, 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 5:24 AM and sets 17 hours, 7 minutes later, at 10:32 PM, while on December 21, the shortest day of the year, it rises at 9:12 AM and sets 7 hours, 24 minutes later, at 4:36 PM.
Sunrise & Sunset with Twilight in September
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 Grande Cache is essentially constant during September, remaining around 0% throughout.
For reference, on August 15, 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
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 Grande Cache is gradually increasing during September, increasing from 4.4 miles per hour to 5.0 miles per hour over the course of the month.
For reference, on December 10, the windiest day of the year, the daily average wind speed is 6.4 miles per hour, while on August 1, the calmest day of the year, the daily average wind speed is 4.1 miles per hour.
Average Wind Speed in September
Wind Direction in September
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 Grande Cache typically lasts for 1.7 months (52 days), from around June 27 to around August 18, rarely starting before June 5, or ending after September 9.
The month of September in Grande Cache is more likely than not fully outside of the growing season, with the chance that a given day is in the growing season rapidly decreasing from 22% to -0% over the course of the month.
Time Spent in Various Temperature Bands and the Growing Season in September
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 Grande Cache are gradually increasing during September, increasing by 87°F, from 665°F to 752°F, over the course of the month.
Growing Degree Days in September
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 Grande Cache is decreasing during September, falling by 1.5 kWh, from 4.6 kWh to 3.1 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in September
For the purposes of this report, the geographical coordinates of Grande Cache are 53.883 deg latitude, -119.136 deg longitude, and 3,832 ft elevation.
The topography within 2 miles of Grande Cache contains very significant variations in elevation, with a maximum elevation change of 1,732 feet and an average elevation above sea level of 3,763 feet. Within 10 miles contains very significant variations in elevation (5,049 feet). Within 50 miles also contains extreme variations in elevation (8,369 feet).
The area within 2 miles of Grande Cache is covered by trees (72%) and sparse vegetation (11%), within 10 miles by trees (88%), and within 50 miles by trees (73%) and sparse vegetation (12%).
This report illustrates the typical weather in Grande Cache 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, Henderickson Automatic Weather Reporting System, in our network suitable to be used as a proxy for the historical temperature and dew point records of Grande Cache.
At a distance of 46 kilometers from Grande Cache, 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 Grande Cache 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 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.