September Weather in Arlington, United States

Last updated: June 24, 2025

In Arlington, United States, the average temperature in September hovers around 14°C (58°F). However, be prepared for temperature fluctuations; it can dip as low as 3°C (37°F) and soar to a maximum of 32°C (90°F). Expect 175 mm (6.9 in) of precipitation over approximately 12 days, contributing to an average humidity level of 76%. Enjoy the diverse climate while exploring this vibrant destination!

September Temperature in Arlington

In September in Arlington, the average temperature is 14°C (58°F). Maximum temperatures can reach up to 32°C (90°F), while minimum temperatures can drop as low as 3°C (37°F). Whether you're planning outdoor adventures or city explorations, be sure to pack for a range of temperatures to fully enjoy your trip.

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

The chart illustrates September temperature patterns in Arlington, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Arlington, September typically has an average temperature of 14°C (58°F), with highs reaching up to 32°C (90°F) and lows dropping to around 3°C (37°F).
JanFebMarAprMayJunJulAugSepOctNovDec373541475459636458474136
Data source: Temperature data for Arlington 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 Arlington

In Arlington in September, the precipitation amount is 175 mm (6.9 in) accumulated over the course of 12 days.

September Precipitation Trends in Arlington

The chart displays monthly precipitation patterns in Arlington, 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 Arlington, September typically receives around 175 mm (6.9 inches) of precipitation spread over approximately 12 days.
JanFebMarAprMayJunJulAugSepOctNovDec3143252562141131043738175302404365
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Arlington

In Arlington in September humidity is 76%. With an average temperature of 14°C (58°F), this humidity feels like a warm, thick blanket wrapping around you, making outdoor activities feel sticky and draining, and prompting travelers to seek shade and stay hydrated often.

September Average Humidity in Arlington

This chart illustrates the average monthly humidity levels in Arlington, 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 Arlington is approximately 76%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec87%86%88%86%82%82%85%77%76%88%88%89%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Arlington

In Arlington 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 Arlington.

Maximum UV Index Levels in Arlington for September

The chart shows the monthly maximum UV Index (UVI) for Arlington 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 Arlington typically reaches 7, which falls under the high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec235689987531
Data source: Arlington 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 Arlington Compares to Other Months

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

This table compares monthly weather conditions in Arlington, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather3°C (37°F)314 mm (12.4 inches)87%low
February Weather2°C (36°F)325 mm (12.8 inches)86%moderate
March Weather5°C (41°F)256 mm (10.1 inches)88%moderate
April Weather8°C (47°F)214 mm (8.4 inches)86%high
May Weather12°C (54°F)113 mm (4.4 inches)82%very high
June Weather15°C (59°F)104 mm (4.1 inches)82%very high
July Weather17°C (63°F)37 mm (1.5 inches)85%very high
August Weather18°C (64°F)38 mm (1.5 inches)77%very high
September Weather14°C (58°F)175 mm (6.9 inches)76%high
October Weather8°C (47°F)302 mm (11.9 inches)88%moderate
November Weather5°C (42°F)404 mm (15.9 inches)88%moderate
December Weather2°C (37°F)365 mm (14.4 inches)89%low

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