Average Weather in August in Portage Michigan, United States
Daily high temperatures decrease by 4°F, from 82°F to 79°F, rarely falling below 69°F or exceeding 90°F.
Daily low temperatures decrease by 4°F, from 63°F to 59°F, rarely falling below 50°F or exceeding 72°F.
For reference, on July 19, the hottest day of the year, temperatures in Portage typically range from 64°F to 83°F, while on January 29, the coldest day of the year, they range from 18°F to 31°F.
Average High and Low Temperature in August
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on August. 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 August
The month of August in Portage experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 33% throughout the month. The lowest chance of overcast or mostly cloudy conditions is 32% on August 26.
The clearest day of the month is August 26, with clear, mostly clear, or partly cloudy conditions 68% of the time.
For reference, on December 31, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 68%, while on August 26, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 68%.
Cloud Cover Categories in August
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Portage, the chance of a wet day over the course of August is gradually decreasing, starting the month at 35% and ending it at 31%.
For reference, the year's highest daily chance of a wet day is 36% on June 13, and its lowest chance is 16% on February 8.
Probability of Precipitation in August
The average sliding 31-day rainfall during August in Portage is essentially constant, remaining about 3.2 inches throughout, and rarely exceeding 5.3 inches or falling below 1.3 inches.
The highest average 31-day accumulation is 3.2 inches on August 5.
Average Monthly Rainfall in August
Over the course of August in Portage, 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, 15 minutes, implying an average daily decrease of 2 minutes, 30 seconds, and weekly decrease of 17 minutes, 29 seconds.
The shortest day of the month is August 31, with 13 hours, 11 minutes of daylight and the longest day is August 1, with 14 hours, 26 minutes of daylight.
Hours of Daylight and Twilight in August
The earliest sunrise of the month in Portage is 6:35 AM on August 1 and the latest sunrise is 31 minutes later at 7:06 AM on August 31.
The latest sunset is 9:01 PM on August 1 and the earliest sunset is 44 minutes earlier at 8:17 PM on August 31.
Daylight saving time is observed in Portage during 2018, but it neither starts nor ends during August, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 6:06 AM and sets 15 hours, 16 minutes later, at 9:22 PM, while on December 21, the shortest day of the year, it rises at 8:07 AM and sets 9 hours, 6 minutes later, at 5:13 PM.
Sunrise & Sunset with Twilight in August
The chance that a given day will be muggy in Portage is rapidly decreasing during August, falling from 36% to 24% over the course of the month.
The highest chance of a muggy day during August is 36% on August 1.
For reference, on August 1, the muggiest day of the year, there are muggy conditions 36% 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 August
The average hourly wind speed in Portage is gradually increasing during August, increasing from 7.8 miles per hour to 8.4 miles per hour over the course of the month.
For reference, on January 15, the windiest day of the year, the daily average wind speed is 12.7 miles per hour, while on August 4, the calmest day of the year, the daily average wind speed is 7.8 miles per hour.
The lowest daily average wind speed during August is 7.8 miles per hour on August 4.
Average Wind Speed in August
Wind Direction in August
Portage is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in Portage is essentially constant during August, remaining within 1°F of 71°F throughout.
The highest average surface water temperature during August is 72°F on August 13.
Average Water Temperature in August
The growing season in Portage typically lasts for 5.7 months (174 days), from around April 25 to around October 16, rarely starting before April 9 or after May 13, and rarely ending before September 26 or after November 6.
The month of August in Portage is reliably fully within the growing season.
Time Spent in Various Temperature Bands and the Growing Season in August
The average accumulated growing degree days in Portage are rapidly increasing during August, increasing by 624°F, from 1,801°F to 2,425°F, over the course of the month.
Growing Degree Days in August
The average daily incident shortwave solar energy in Portage is gradually decreasing during August, falling by 0.9 kWh, from 6.5 kWh to 5.6 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in August
For the purposes of this report, the geographical coordinates of Portage are 42.201 deg latitude, -85.580 deg longitude, and 863 ft elevation.
The topography within 2 miles of Portage is essentially flat, with a maximum elevation change of 66 feet and an average elevation above sea level of 863 feet. Within 10 miles is essentially flat (305 feet). Within 50 miles contains only modest variations in elevation (646 feet).
The area within 2 miles of Portage is covered by artificial surfaces (77%), within 10 miles by cropland (44%) and artificial surfaces (27%), and within 50 miles by cropland (63%) and trees (22%).
This report illustrates the typical weather in Portage 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 Portage.
For each station, the records are corrected for the elevation difference between that station and Portage 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 Portage is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Portage and a given station.
The stations contributing to this reconstruction are: Kalamazoo-Battle Creek International Airport (92%, 4.4 kilometers, northeast); Hree Rivers Municipal Dr Haines Airport (6%, 27 kilometers, south); and South Haven Area Regional Airport (1.9%, 58 kilometers, west).
Time zones for aiports and weather stations are provided by AskGeo.com .