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September Weather in Union City, United States

Last updated: June 24, 2025

In September, the average temperature in Union City, United States is a comfortable 24°C (75°F). Expect a range from a cool 10°C (50°F) to a warm 36°C (97°F). Be prepared for some rain, with an average precipitation of 86 mm (3.4 in) spread over 7 days. The humidity tends to be quite high, averaging around 75%, contributing to the overall tropical feel of the region.

September Temperature in Union City

In September in Union City, the average temperature is 24°C (75°F). The maximum can reach 36°C (97°F), while the minimum can be as low as 10°C (50°F). Whether you're looking to enjoy warm days or cool evenings, this climate provides a comfortable backdrop for exploring and enjoying all that Union City has to offer.

September Weather in Union City: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Union City, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Union City, September typically has an average temperature of 24°C (75°F), with highs reaching up to 36°C (97°F) and lows dropping to around 10°C (50°F).
JanFebMarAprMayJunJulAugSepOctNovDec394352597178817875634844
Data source: Temperature data for Union City 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 Union City

In Union City in September, the total precipitation amount is 86 mm (3.4 in) over a span of 7 days.

September Precipitation Trends in Union City

The chart displays monthly precipitation patterns in Union City, 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 Union City, September typically receives around 86 mm (3.4 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec1051611731451241091149786113104117
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Union City

In Union City in September humidity is 75%. With average temperature 24°C (75°F), this humidity feels like a thick blanket wrapping around you, making outdoor activities feel especially stifling and leaving you yearning for cool breezes and refreshingly cold drinks.

September Average Humidity in Union City

This chart illustrates the average monthly humidity levels in Union City, 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 Union City is approximately 75%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec86%84%84%80%82%83%80%76%75%75%85%88%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Union City

In Union City in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Union City.

Maximum UV Index Levels in Union City for September

The chart shows the monthly maximum UV Index (UVI) for Union City 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 Union City typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec36710111111109753
Data source: Union City 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 Union City Compares to Other Months

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

This table compares monthly weather conditions in Union City, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather4°C (39°F)105 mm (4.1 inches)86%moderate
February Weather6°C (43°F)161 mm (6.3 inches)84%high
March Weather11°C (52°F)173 mm (6.8 inches)84%high
April Weather15°C (59°F)145 mm (5.7 inches)80%very high
May Weather21°C (71°F)124 mm (4.9 inches)82%extreme
June Weather25°C (78°F)109 mm (4.3 inches)83%extreme
July Weather27°C (81°F)113 mm (4.5 inches)79%extreme
August Weather26°C (79°F)97 mm (3.8 inches)76%very high
September Weather24°C (75°F)86 mm (3.4 inches)75%very high
October Weather17°C (63°F)113 mm (4.4 inches)74%high
November Weather9°C (48°F)104 mm (4.1 inches)85%moderate
December Weather7°C (45°F)117 mm (4.6 inches)88%moderate

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