Average Weather in September in Mankato Minnesota, United States
Daily high temperatures decrease by 10°F, from 77°F to 67°F, rarely falling below 54°F or exceeding 87°F.
Daily low temperatures decrease by 11°F, from 58°F to 47°F, rarely falling below 35°F or exceeding 68°F.
For reference, on July 18, the hottest day of the year, temperatures in Mankato typically range from 64°F to 83°F, while on January 15, the coldest day of the year, they range from 9°F to 24°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 Mankato experiences gradually increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 31% to 36%.
The clearest day of the month is September 1, with clear, mostly clear, or partly cloudy conditions 69% of the time.
For reference, on February 6, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 59%, while on July 27, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 73%.
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 Mankato, the chance of a wet day over the course of September is very rapidly decreasing, starting the month at 33% and ending it at 23%.
For reference, the year's highest daily chance of a wet day is 42% on June 9, and its lowest chance is 7% on February 4.
Probability of Precipitation in September
The average sliding 31-day rainfall during September in Mankato is decreasing, starting the month at 3.0 inches, when it rarely exceeds 5.4 inches or falls below 1.0 inches, and ending the month at 2.4 inches, when it rarely exceeds 4.7 inches or falls below 0.5 inches.
Average Monthly Rainfall in September
Over the course of September in Mankato, 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, 27 minutes, implying an average daily decrease of 3 minutes, 0 seconds, and weekly decrease of 20 minutes, 59 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, 13 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in Mankato is 6:39 AM on September 1 and the latest sunrise is 33 minutes later at 7:12 AM on September 30.
The latest sunset is 7:51 PM on September 1 and the earliest sunset is 53 minutes earlier at 6:58 PM on September 30.
Daylight saving time is observed in Mankato 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 5:32 AM and sets 15 hours, 31 minutes later, at 9:03 PM, while on December 21, the shortest day of the year, it rises at 7:48 AM and sets 8 hours, 52 minutes later, at 4:40 PM.
Sunrise & Sunset with Twilight in September
The chance that a given day will be muggy in Mankato is rapidly decreasing during September, falling from 19% to 2% over the course of the month.
For reference, on July 21, the muggiest day of the year, there are muggy conditions 36% of the time, while on November 3, 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 Mankato is increasing during September, increasing from 9.6 miles per hour to 11.0 miles per hour over the course of the month.
For reference, on April 1, the windiest day of the year, the daily average wind speed is 12.9 miles per hour, while on August 3, the calmest day of the year, the daily average wind speed is 8.5 miles per hour.
Average Wind Speed in September
Wind Direction in September
The growing season in Mankato typically lasts for 5.5 months (168 days), from around April 22 to around October 7, rarely starting before April 3 or after May 11, and rarely ending before September 19 or after October 25.
The month of September in Mankato 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 69% 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 Mankato are increasing during September, increasing by 365°F, from 2,342°F to 2,707°F, over the course of the month.
Growing Degree Days in September
The average daily incident shortwave solar energy in Mankato is decreasing during September, falling by 1.4 kWh, from 5.5 kWh to 4.1 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 Mankato are 44.159 deg latitude, -94.009 deg longitude, and 961 ft elevation.
The topography within 2 miles of Mankato contains only modest variations in elevation, with a maximum elevation change of 256 feet and an average elevation above sea level of 881 feet. Within 10 miles also contains only modest variations in elevation (325 feet). Within 50 miles contains only modest variations in elevation (738 feet).
The area within 2 miles of Mankato is covered by artificial surfaces (63%), trees (25%), and cropland (11%), within 10 miles by cropland (83%), and within 50 miles by cropland (94%).
This report illustrates the typical weather in Mankato 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 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Mankato.
For each station, the records are corrected for the elevation difference between that station and Mankato 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 Mankato is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Mankato and a given station.
The stations contributing to this reconstruction are: Mankato Regional Airport (83%, 10 kilometers, northeast); New Ulm Municipal Airport (9%, 43 kilometers, northwest); and St. James, St. James Municipal Airport (8%, 48 kilometers, southwest).
Time zones for aiports and weather stations are provided by AskGeo.com .