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September Weather in Fort Defiance, United States

Last updated: June 24, 2025

In September, the average temperature in Fort Defiance, United States hovers around 18°C (65°F). Expect a minimum of 0°C (33°F) and a maximum of 33°C (92°F). During this month, you can anticipate about 33 mm (1.3 in) of precipitation spread across 5 days, with an average humidity level of 62%.

September Temperature in Fort Defiance

In September in Fort Defiance, the average temperature is 18°C (65°F). The maximum can reach 33°C (92°F) and the minimum can be as low as 0°C (33°F). Pack accordingly to enjoy a range of activities in comfortable temperatures.

September Weather in Fort Defiance: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Fort Defiance, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Fort Defiance, 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 0°C (33°F).
JanFebMarAprMayJunJulAugSepOctNovDec293240515971737265524130
Data source: Temperature data for Fort Defiance 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 Fort Defiance

In Fort Defiance in September, the precipitation amount is 33 mm (1.3 in) over the course of 5 days.

September Precipitation Trends in Fort Defiance

The chart displays monthly precipitation patterns in Fort Defiance, 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 Fort Defiance, September typically receives around 33 mm (1.3 inches) of precipitation spread over approximately 5 days.
JanFebMarAprMayJunJulAugSepOctNovDec31364316216482433271929
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Fort Defiance

In Fort Defiance in September, humidity is 62%. With an average temperature of 18°C (65°F), this humidity feels like a warm embrace, making outdoor activities enjoyable yet mildly sticky, perfect for leisurely strolls but a bit challenging for vigorous excursions.

September Average Humidity in Fort Defiance

This chart illustrates the average monthly humidity levels in Fort Defiance, 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 Fort Defiance is approximately 62%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec81%83%71%61%48%36%37%46%62%74%82%82%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Fort Defiance

In Fort Defiance in September, the maximum UV index reaches 11, which corresponds to an extreme Exposure Category. With a time to burn of just 10 minutes, it's essential to take precautions. For more details, you can check the Hourly UV Index in Fort Defiance.

Maximum UV Index Levels in Fort Defiance for September

The chart shows the monthly maximum UV Index (UVI) for Fort Defiance 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 Fort Defiance typically reaches 11, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec589111213131211864
Data source: Fort Defiance 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 Fort Defiance Compares to Other Months

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

This table compares monthly weather conditions in Fort Defiance, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-2°C (29°F)31 mm (1.2 inches)81%moderate
February Weather0°C (33°F)36 mm (1.4 inches)83%very high
March Weather5°C (40°F)43 mm (1.7 inches)71%very high
April Weather10°C (51°F)16 mm (0.6 inches)61%extreme
May Weather15°C (59°F)21 mm (0.8 inches)48%extreme
June Weather22°C (71°F)6 mm (0.2 inches)36%extreme
July Weather23°C (73°F)48 mm (1.9 inches)37%extreme
August Weather22°C (72°F)24 mm (0.9 inches)46%extreme
September Weather18°C (65°F)33 mm (1.3 inches)62%extreme
October Weather11°C (52°F)26 mm (1.0 inches)74%very high
November Weather5°C (42°F)19 mm (0.7 inches)82%high
December Weather-1°C (31°F)29 mm (1.2 inches)82%moderate

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