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September Weather in Pontiac, United States

Last updated: June 24, 2025

In Pontiac, United States, the average temperature in September hovers around 21°C (69°F). Expect minimums of 5°C (41°F) and maximums reaching 35°C (95°F). Rain is likely, with 82 mm (3.2 in) of precipitation spread over about 9 days, contributing to an average humidity of 80%. Be prepared for a mix of warm days and refreshing showers!

September Temperature in Pontiac

In September in Pontiac, the average temperature is 21°C (69°F). The maximum can reach 35°C (95°F) and the minimum can be as low as 5°C (41°F). It’s advisable to pack versatile clothing to accommodate both warm days and cooler evenings during your travels.

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

The chart illustrates September temperature patterns in Pontiac, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Pontiac, September typically has an average temperature of 21°C (69°F), with highs reaching up to 35°C (95°F) and lows dropping to around 5°C (41°F).
JanFebMarAprMayJunJulAugSepOctNovDec262841506373767469564034
Data source: Temperature data for Pontiac 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 Pontiac

In Pontiac in September, the total precipitation amount is 82 mm (3.2 in), occurring over a span of 9 days.

September Precipitation Trends in Pontiac

The chart displays monthly precipitation patterns in Pontiac, 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 Pontiac, September typically receives around 82 mm (3.2 inches) of precipitation spread over approximately 9 days.
JanFebMarAprMayJunJulAugSepOctNovDec62689911716313510092821315656
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Pontiac

In Pontiac in September, humidity is 80%. With an average temperature of 21°C (69°F), this humidity feels like a warm, sticky embrace, making outdoor activities a bit challenging for travelers as the air becomes heavy and can lead to fatigue while sightseeing.

September Average Humidity in Pontiac

This chart illustrates the average monthly humidity levels in Pontiac, 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 Pontiac is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%83%84%85%79%82%80%81%80%82%88%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Pontiac

In Pontiac in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Pontiac.

Maximum UV Index Levels in Pontiac for September

The chart shows the monthly maximum UV Index (UVI) for Pontiac 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 Pontiac typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec35689101098642
Data source: Pontiac 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 Pontiac Compares to Other Months

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

This table compares monthly weather conditions in Pontiac, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-3°C (27°F)62 mm (2.4 inches)82%moderate
February Weather-2°C (29°F)68 mm (2.7 inches)83%moderate
March Weather5°C (41°F)99 mm (3.9 inches)84%high
April Weather10°C (51°F)117 mm (4.6 inches)85%very high
May Weather17°C (64°F)163 mm (6.4 inches)79%very high
June Weather23°C (74°F)135 mm (5.3 inches)82%very high
July Weather25°C (76°F)100 mm (3.9 inches)80%very high
August Weather23°C (74°F)92 mm (3.6 inches)81%very high
September Weather21°C (69°F)82 mm (3.2 inches)80%very high
October Weather13°C (56°F)131 mm (5.2 inches)82%high
November Weather4°C (40°F)56 mm (2.2 inches)88%moderate
December Weather1°C (34°F)56 mm (2.2 inches)84%low

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