Average Weather in September in Spirit Lake Iowa, 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 12°F, from 57°F to 46°F, rarely falling below 33°F or exceeding 67°F.
For reference, on July 5, the hottest day of the year, temperatures in Spirit Lake typically range from 63°F to 83°F, while on January 15, the coldest day of the year, they range from 9°F to 25°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
Volgograd, Russia (5,622 miles away); Almaty, Kazakhstan (6,435 miles); and Jiuquan, China (6,635 miles) are the far-away foreign places with temperatures most similar to Spirit Lake (view comparison).
The month of September in Spirit Lake experiences gradually increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 30% to 35%.
The clearest day of the month is September 1, with clear, mostly clear, or partly cloudy conditions 70% of the time.
For reference, on February 3, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 57%, while on July 28, 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 Spirit Lake, the chance of a wet day over the course of September is gradually decreasing, starting the month at 30% and ending it at 26%.
For reference, the year's highest daily chance of a wet day is 41% on June 7, and its lowest chance is 7% on February 12.
Probability of Precipitation in September
The average sliding 31-day rainfall during September in Spirit Lake is decreasing, starting the month at 3.0 inches, when it rarely exceeds 5.9 inches or falls below 1.1 inches, and ending the month at 2.5 inches, when it rarely exceeds 5.1 inches or falls below 0.6 inches.
Average Monthly Rainfall in September
Over the course of September in Spirit Lake, 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, 25 minutes, implying an average daily decrease of 2 minutes, 55 seconds, and weekly decrease of 20 minutes, 27 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, 11 minutes of daylight.
Hours of Daylight and Twilight in September
The earliest sunrise of the month in Spirit Lake is 6:44 AM on September 1 and the latest sunrise is 32 minutes later at 7:16 AM on September 30.
The latest sunset is 7:55 PM on September 1 and the earliest sunset is 52 minutes earlier at 7:03 PM on September 30.
Daylight saving time is observed in Spirit Lake 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 5:39 AM and sets 15 hours, 25 minutes later, at 9:04 PM, while on December 21, the shortest day of the year, it rises at 7:49 AM and sets 8 hours, 57 minutes later, at 4:47 PM.
Sunrise & Sunset with Twilight in September
The chance that a given day will be muggy in Spirit Lake is rapidly decreasing during September, falling from 22% to 2% over the course of the month.
For reference, on July 21, the muggiest day of the year, there are muggy conditions 39% 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 Spirit Lake is increasing during September, increasing from 9.9 miles per hour to 11.4 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 13.7 miles per hour, while on August 3, the calmest day of the year, the daily average wind speed is 8.7 miles per hour.
Average Wind Speed in September
Wind Direction in September
The growing season in Spirit Lake typically lasts for 5.2 months (157 days), from around April 28 to around October 2, rarely starting before April 10 or after May 16, and rarely ending before September 14 or after October 20.
The month of September in Spirit Lake 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 55% 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 Spirit Lake are increasing during September, increasing by 355°F, from 2,257°F to 2,612°F, over the course of the month.
Growing Degree Days in September
The average daily incident shortwave solar energy in Spirit Lake is decreasing during September, falling by 1.3 kWh, from 5.6 kWh to 4.3 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 Spirit Lake are 43.422 deg latitude, -95.102 deg longitude, and 1,434 ft elevation.
The topography within 2 miles of Spirit Lake is essentially flat, with a maximum elevation change of 92 feet and an average elevation above sea level of 1,433 feet. Within 10 miles is essentially flat (217 feet). Within 50 miles contains only modest variations in elevation (797 feet).
The area within 2 miles of Spirit Lake is covered by cropland (51%), artificial surfaces (27%), and water (20%), within 10 miles by cropland (87%), and within 50 miles by cropland (98%).
This report illustrates the typical weather in Spirit Lake 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 Spirit Lake.
For each station, the records are corrected for the elevation difference between that station and Spirit Lake 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 Spirit Lake is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Spirit Lake and a given station.
The stations contributing to this reconstruction are: Jackson Municipal Airport (31%, 27 kilometers, north); Estherville Municipal Airport (28%, 29 kilometers, east); Spencer Municipal Airport (27%, 30 kilometers, south); and Worthington Municipal Airport (14%, 46 kilometers, northwest).
Time zones for aiports and weather stations are provided by AskGeo.com .