Average Weather in September in Delta Utah, United States
Daily high temperatures decrease by 12°F, from 86°F to 74°F, rarely falling below 62°F or exceeding 92°F.
Daily low temperatures decrease by 12°F, from 56°F to 45°F, rarely falling below 36°F or exceeding 64°F.
For reference, on July 13, the hottest day of the year, temperatures in Delta typically range from 62°F to 93°F, while on January 4, the coldest day of the year, they range from 21°F to 36°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 Delta experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 21% throughout the month. The lowest chance of overcast or mostly cloudy conditions is 20% on September 11.
The clearest day of the month is September 11, with clear, mostly clear, or partly cloudy conditions 80% of the time.
For reference, on March 2, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 51%, while on September 11, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 80%.
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 Delta, the chance of a wet day over the course of September is essentially constant, remaining around 13% throughout.
For reference, the year's highest daily chance of a wet day is 19% on May 2, and its lowest chance is 6% on July 3.
Probability of Precipitation in September
The average sliding 31-day rainfall during September in Delta is gradually increasing, starting the month at 0.6 inches, when it rarely exceeds 1.3 inches or falls below 0.1 inches, and ending the month at 0.9 inches, when it rarely exceeds 1.8 inches or falls below 0.1 inches.
Average Monthly Rainfall in September
Over the course of September in Delta, 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, 13 minutes, implying an average daily decrease of 2 minutes, 32 seconds, and weekly decrease of 17 minutes, 43 seconds.
The shortest day of the month is September 30, with 11 hours, 47 minutes of daylight and the longest day is September 1, with 13 hours, 1 minute of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in Delta is 6:59 AM on September 1 and the latest sunrise is 27 minutes later at 7:26 AM on September 30.
The latest sunset is 8:00 PM on September 1 and the earliest sunset is 47 minutes earlier at 7:13 PM on September 30.
Daylight saving time is observed in Delta during 2020, but it neither starts nor ends during September, so the entire month is in daylight saving time.
For reference, on June 20, the longest day of the year, the Sun rises at 6:03 AM and sets 14 hours, 57 minutes later, at 9:00 PM, while on December 21, the shortest day of the year, it rises at 7:46 AM and sets 9 hours, 24 minutes later, at 5:10 PM.
Sunrise & Sunset with Twilight in September
The chance that a given day will be muggy in Delta is essentially constant during September, remaining around 0% throughout.
For reference, on July 18, 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
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in Delta is gradually decreasing during September, decreasing from 7.3 miles per hour to 6.8 miles per hour over the course of the month.
For reference, on April 4, the windiest day of the year, the daily average wind speed is 8.6 miles per hour, while on January 7, the calmest day of the year, the daily average wind speed is 6.2 miles per hour.
The highest daily average wind speed during September is 7.3 miles per hour on September 1.
Average Wind Speed in September
The hourly average wind direction in Delta throughout September is predominantly from the south, with a peak proportion of 50% on September 1.
Wind Direction in September
The growing season in Delta typically lasts for 5.5 months (167 days), from around April 28 to around October 12, rarely starting before April 8 or after May 16, and rarely ending before September 23 or after November 2.
The month of September in Delta 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 79% 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 Delta are increasing during September, increasing by 439°F, from 2,684°F to 3,123°F, over the course of the month.
Growing Degree Days in September
The average daily incident shortwave solar energy in Delta is decreasing during September, falling by 1.3 kWh, from 6.5 kWh to 5.2 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 Delta are 39.352 deg latitude, -112.577 deg longitude, and 4,626 ft elevation.
The topography within 2 miles of Delta contains only modest variations in elevation, with a maximum elevation change of 102 feet and an average elevation above sea level of 4,633 feet. Within 10 miles also contains only modest variations in elevation (407 feet). Within 50 miles contains only modest variations in elevation (5,899 feet).
The area within 2 miles of Delta is covered by cropland (63%) and shrubs (31%), within 10 miles by shrubs (61%) and cropland (29%), and within 50 miles by shrubs (79%).
This report illustrates the typical weather in Delta 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 are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Delta.
For each station, the records are corrected for the elevation difference between that station and Delta 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 Delta is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Delta and a given station.
The stations contributing to this reconstruction are: Milford Municipal Airport (35%, 111 kilometers, south); Provo Municipal Airport (31%, 121 kilometers, northeast); Carbon County Airport (20%, 159 kilometers, east); and Ely Airport-Yelland Field (14%, 196 kilometers, west).
Time zones for aiports and weather stations are provided by AskGeo.com .