Average Weather in September in Gregory South Dakota, United States
Daily high temperatures decrease by 13°F, from 82°F to 70°F, rarely falling below 55°F or exceeding 93°F.
Daily low temperatures decrease by 13°F, from 59°F to 46°F, rarely falling below 35°F or exceeding 68°F.
For reference, on July 19, the hottest day of the year, temperatures in Gregory typically range from 64°F to 88°F, while on January 2, the coldest day of the year, they range from 14°F to 32°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 Gregory experiences gradually increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 29% to 34%.
The clearest day of the month is September 2, with clear, mostly clear, or partly cloudy conditions 71% of the time.
For reference, on March 15, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 53%, while on July 27, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 76%.
Cloud Cover Categories in September
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. In Gregory, the chance of a wet day over the course of September is decreasing, starting the month at 22% and ending it at 16%.
For reference, the year's highest daily chance of a wet day is 41% on June 7, and its lowest chance is 3% on January 15.
Probability of Precipitation in September
The average sliding 31-day rainfall during September in Gregory is essentially constant, remaining about 1.8 inches throughout, and rarely exceeding 4.1 inches or falling below 0.4 inches.
Average Monthly Rainfall in September
Over the course of September in Gregory, 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, 24 minutes, implying an average daily decrease of 2 minutes, 54 seconds, and weekly decrease of 20 minutes, 19 seconds.
The shortest day of the month is September 30, with 11 hours, 46 minutes of daylight and the longest day is September 1, with 13 hours, 10 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in Gregory is 7:02 AM on September 1 and the latest sunrise is 32 minutes later at 7:34 AM on September 30.
The latest sunset is 8:12 PM on September 1 and the earliest sunset is 52 minutes earlier at 7:20 PM on September 30.
Daylight saving time is observed in Gregory 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 5:57 AM and sets 15 hours, 24 minutes later, at 9:21 PM, while on December 21, the shortest day of the year, it rises at 8:06 AM and sets 8 hours, 59 minutes later, at 5:05 PM.
Sunrise & Sunset with Twilight in September
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
The chance that a given day will be muggy in Gregory is decreasing during September, falling from 10% to 0% over the course of the month.
For reference, on July 25, the muggiest day of the year, there are muggy conditions 23% 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
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in Gregory is gradually increasing during September, increasing from 10.7 miles per hour to 11.6 miles per hour over the course of the month.
For reference, on April 8, the windiest day of the year, the daily average wind speed is 12.7 miles per hour, while on August 2, the calmest day of the year, the daily average wind speed is 9.5 miles per hour.
Average Wind Speed in September
The hourly average wind direction in Gregory throughout September is predominantly from the south, with a peak proportion of 45% on September 2.
Wind Direction in September
The growing season in Gregory typically lasts for 5.3 months (162 days), from around May 1 to around October 10, rarely starting before April 12 or after May 21, and rarely ending before September 21 or after October 30.
The month of September in Gregory is more likely than not fully within the growing season, with the chance that a given day is in the growing season rapidly decreasing from 100% to 75% over the course of the month.
Time Spent in Various Temperature Bands and the Growing Season in September
The average accumulated growing degree days in Gregory are increasing during September, increasing by 401°F, from 2,432°F to 2,833°F, over the course of the month.
Growing Degree Days in September
The average daily incident shortwave solar energy in Gregory is decreasing during September, falling by 1.4 kWh, from 5.8 kWh to 4.4 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 Gregory are 43.232 deg latitude, -99.430 deg longitude, and 2,165 ft elevation.
The topography within 2 miles of Gregory contains only modest variations in elevation, with a maximum elevation change of 187 feet and an average elevation above sea level of 2,176 feet. Within 10 miles contains only modest variations in elevation (669 feet). Within 50 miles contains significant variations in elevation (1,506 feet).
The area within 2 miles of Gregory is covered by grassland (75%) and cropland (25%), within 10 miles by grassland (82%) and cropland (18%), and within 50 miles by grassland (73%) and cropland (23%).
This report illustrates the typical weather in Gregory, 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Gregory.
For each station, the records are corrected for the elevation difference between that station and Gregory 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 Gregory is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Gregory and a given station.
The stations contributing to this reconstruction are: Winner Regional Airport (50%, 38 kilometers, northwest); Chamberlain, Chamberlain Municipal Airport (24%, 60 kilometers, north); Ainsworth Municipal Airport (14%, 87 kilometers, southwest); and The O'Neill Municipal Airport (11%, 104 kilometers, southeast).
Time zones for airports and weather stations are provided by AskGeo.com .