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September Weather in Portage, United States

Last updated: June 24, 2025

In September, the average temperature in Portage, United States reaches a comfortable 18°C (65°F). However, it can vary significantly, with minimums dipping to 1°C (35°F) and maximums soaring up to 33°C (92°F). Expect 101 mm (4.0 in) of precipitation spread over 10 days, contributing to an average humidity of 79%. Stay prepared for a mix of weather conditions!

September Temperature in Portage

In September in Portage, the average temperature is 18°C (65°F), with maximums that can reach 33°C (92°F) and minimums that can dip as low as 1°C (35°F). This makes it a great time to explore, so be sure to pack for both warm days and cooler evenings!

September Weather in Portage: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Portage, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Portage, September typically has an average temperature of 18°C (65°F), with highs reaching up to 33°C (92°F) and lows dropping to around 1°C (35°F).
JanFebMarAprMayJunJulAugSepOctNovDec202135455970747164503628
Data source: Temperature data for Portage generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Portage

In Portage in September, the precipitation amount is 101 mm (4.0 in) spread over the course of 10 days.

September Precipitation Trends in Portage

The chart displays monthly precipitation patterns in Portage, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Portage, September typically receives around 101 mm (4.0 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec47535895127113951051011114445
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Portage

In Portage in September, humidity is 79%. With an average temperature of 18°C (65°F), this humidity feels like walking through a warm mist, making traveling slightly uncomfortable and sticky, but offering a refreshing escape when you find moments of shade or a breeze.

September Average Humidity in Portage

This chart illustrates the average monthly humidity levels in Portage, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Portage is approximately 79%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%85%85%85%78%80%78%76%79%83%88%82%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Portage

In Portage in September, the maximum UV index is 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check the Hourly UV Index in Portage.

Maximum UV Index Levels in Portage for September

The chart shows the monthly maximum UV Index (UVI) for Portage in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Portage typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec24589101097532
Data source: Portage September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Portage Compares to Other Months

Weather in Portage varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Portage, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Portage, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-6°C (21°F)46 mm (1.8 inches)85%low
February Weather-6°C (21°F)53 mm (2.1 inches)85%moderate
March Weather2°C (35°F)58 mm (2.3 inches)85%moderate
April Weather7°C (45°F)95 mm (3.8 inches)85%very high
May Weather15°C (59°F)127 mm (5.0 inches)78%very high
June Weather21°C (70°F)113 mm (4.4 inches)80%very high
July Weather23°C (74°F)95 mm (3.7 inches)78%very high
August Weather21°C (71°F)105 mm (4.1 inches)76%very high
September Weather18°C (65°F)101 mm (4.0 inches)79%high
October Weather10°C (51°F)111 mm (4.4 inches)83%moderate
November Weather2°C (36°F)44 mm (1.7 inches)88%moderate
December Weather-2°C (28°F)45 mm (1.8 inches)81%low

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