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September Weather in Hartley, United States

Last updated: June 24, 2025

In Hartley, United States, the average temperature in September is a pleasant 22°C (71°F). However, be prepared for variations, as temperatures can dip to a cool 2°C (35°F) or soar to a scorching 39°C (102°F). During this month, you can expect 31 mm (1.2 in) of precipitation over approximately 5 days, and the average humidity hovers around 76%, adding to the overall climate experience.

September Temperature in Hartley

In September in Hartley, the average temperature is 22°C (71°F). Maximums can reach 39°C (102°F) and minimums can be as low as 2°C (35°F). Travelers should be prepared for a wide range of temperatures and pack accordingly.

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

The chart illustrates September temperature patterns in Hartley, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Hartley, September typically has an average temperature of 22°C (71°F), with highs reaching up to 39°C (102°F) and lows dropping to around 2°C (35°F).
JanFebMarAprMayJunJulAugSepOctNovDec373849556676797771574739
Data source: Temperature data for Hartley 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 Hartley

In Hartley in September, the precipitation amount is 31 mm (1.2 in) spread over 5 days.

September Precipitation Trends in Hartley

The chart displays monthly precipitation patterns in Hartley, 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 Hartley, September typically receives around 31 mm (1.2 inches) of precipitation spread over approximately 5 days.
JanFebMarAprMayJunJulAugSepOctNovDec151039375943295431501214
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Hartley

In Hartley in September, humidity is 76%. With an average temperature of 22°C (71°F), this humidity feels like traveling through a warm, dense mist that clings to your skin, making every step feel heavier and the air seem thicker, which can be quite draining for outdoor activities.

September Average Humidity in Hartley

This chart illustrates the average monthly humidity levels in Hartley, 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 Hartley is approximately 76%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec74%75%61%62%69%74%75%78%76%76%80%77%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Hartley

In Hartley in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Hartley.

Maximum UV Index Levels in Hartley for September

The chart shows the monthly maximum UV Index (UVI) for Hartley 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 Hartley typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468111112121110754
Data source: Hartley 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 Hartley Compares to Other Months

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

This table compares monthly weather conditions in Hartley, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather3°C (37°F)15 mm (0.6 inches)74%moderate
February Weather3°C (39°F)10 mm (0.4 inches)75%high
March Weather10°C (50°F)39 mm (1.5 inches)61%very high
April Weather13°C (56°F)37 mm (1.5 inches)61%extreme
May Weather19°C (66°F)58 mm (2.3 inches)69%extreme
June Weather24°C (76°F)43 mm (1.7 inches)74%extreme
July Weather26°C (79°F)29 mm (1.1 inches)75%extreme
August Weather25°C (77°F)54 mm (2.1 inches)78%extreme
September Weather22°C (71°F)31 mm (1.2 inches)76%very high
October Weather14°C (57°F)50 mm (2.0 inches)76%high
November Weather8°C (47°F)11 mm (0.5 inches)80%moderate
December Weather4°C (40°F)14 mm (0.6 inches)77%moderate

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