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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 hovers around 20°C (69°F). Expect a minimum chill of 4°C (40°F) and a warm peak of 33°C (92°F). With an average humidity of 78%, you'll feel the tropical air as you experience a total precipitation of 81 mm (3.2 in) across about 7 days. Plan accordingly to enjoy all that this vibrant locale has to offer!

September Temperature in Union City

In September in Union City, the average temperature is 20°C (69°F). Maximums can reach 33°C (92°F), while minimums can drop as low as 4°C (40°F). This varied climate makes Union City an ideal destination for travelers seeking both warmth and cooler experiences.

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 20°C (69°F), with highs reaching up to 33°C (92°F) and lows dropping to around 4°C (40°F).
JanFebMarAprMayJunJulAugSepOctNovDec293241516372757368574135
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 precipitation amount is 81 mm (3.2 in) over a period 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 81 mm (3.2 inches) of precipitation spread over approximately 7 days.
JanFebMarAprMayJunJulAugSepOctNovDec749610710013812711010781998874
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 78%. With an average temperature of 20°C (69°F), this humidity feels like a warm, enveloping blanket, making travel somewhat uncomfortable as sweat clings to your skin and the air feels thick and heavy, urging you to seek out shaded areas and refreshing 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 78%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%87%87%88%81%82%81%78%78%82%89%86%
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 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 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 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098642
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 Weather-1°C (30°F)74 mm (2.9 inches)88%moderate
February Weather0°C (33°F)96 mm (3.8 inches)87%moderate
March Weather5°C (42°F)107 mm (4.2 inches)87%high
April Weather11°C (51°F)99 mm (3.9 inches)87%very high
May Weather17°C (63°F)138 mm (5.4 inches)81%very high
June Weather22°C (72°F)127 mm (5.0 inches)82%very high
July Weather24°C (76°F)110 mm (4.3 inches)81%very high
August Weather23°C (73°F)107 mm (4.2 inches)78%very high
September Weather20°C (69°F)81 mm (3.2 inches)78%very high
October Weather14°C (57°F)99 mm (3.9 inches)82%high
November Weather5°C (41°F)88 mm (3.5 inches)89%moderate
December Weather2°C (35°F)74 mm (2.9 inches)86%low

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