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September Weather in Alliance, United States

Last updated: June 24, 2025

Average Temperature Overview for Alliance, United States in September

The average temperature in Alliance, United States during September hovers around 18°C (65°F). Expect minimum temperatures to descend to 1°C (33°F) and maximums soaring up to 37°C (100°F). With an average humidity of 75%, it’s a time when you can anticipate some moisture, as precipitation amounts reach 29 mm (1.2 in) over 5 days.

September Temperature in Alliance

In September in Alliance, the average temperature is 18°C (65°F). Maximums can reach 37°C (100°F), while minimums can drop as low as 1°C (33°F). Be prepared for a wide range of temperatures, ensuring you pack both light clothing for the heat and warmer layers for the cooler moments.

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

The chart illustrates September temperature patterns in Alliance, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Alliance, September typically has an average temperature of 18°C (65°F), with highs reaching up to 37°C (100°F) and lows dropping to around 1°C (33°F).
JanFebMarAprMayJunJulAugSepOctNovDec292639455570757265473932
Data source: Temperature data for Alliance 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 Alliance

In Alliance in September, the precipitation amount is 29 mm (1.2 in) over a period of 5 days.

September Precipitation Trends in Alliance

The chart displays monthly precipitation patterns in Alliance, 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 Alliance, September typically receives around 29 mm (1.2 inches) of precipitation spread over approximately 5 days.
JanFebMarAprMayJunJulAugSepOctNovDec1122615212341424429442218
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Alliance

In Alliance in September, humidity is 75%. With an average temperature of 18°C (65°F), this humidity feels like a warm, enveloping blanket that can make outdoor exploration feel a bit stifling, potentially leading to discomfort during travel activities.

September Average Humidity in Alliance

This chart illustrates the average monthly humidity levels in Alliance, 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 Alliance is approximately 75%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec72%76%62%60%74%82%82%84%75%73%74%77%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Alliance

In Alliance 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 Alliance.

Maximum UV Index Levels in Alliance for September

The chart shows the monthly maximum UV Index (UVI) for Alliance 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 Alliance typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec3579101111109643
Data source: Alliance 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 Alliance Compares to Other Months

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

This table compares monthly weather conditions in Alliance, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-2°C (29°F)11 mm (0.5 inches)72%moderate
February Weather-3°C (27°F)22 mm (0.9 inches)76%moderate
March Weather4°C (39°F)61 mm (2.4 inches)61%high
April Weather7°C (46°F)52 mm (2.1 inches)60%very high
May Weather13°C (55°F)123 mm (4.8 inches)74%very high
June Weather21°C (70°F)41 mm (1.6 inches)82%extreme
July Weather24°C (76°F)42 mm (1.6 inches)82%extreme
August Weather22°C (72°F)44 mm (1.7 inches)84%very high
September Weather18°C (65°F)29 mm (1.2 inches)75%very high
October Weather8°C (47°F)44 mm (1.7 inches)73%high
November Weather4°C (40°F)22 mm (0.9 inches)74%moderate
December Weather0°C (32°F)18 mm (0.7 inches)77%moderate

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