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August Weather in Helena, United States

Last updated: June 24, 2025

In August, the average temperature in Helena, United States is a warm 28°C (82°F). Visitors should be prepared for a range of temperatures, with minimums dipping to 17°C (63°F) and soaring to a maximum of 41°C (106°F). Humidity levels average around 79%, creating a lush atmosphere. Expect precipitation of about 106 mm (4.2 in) over 18 days, so pack accordingly!

August Temperature in Helena

In August in Helena, the average temperature is 28°C (82°F). The maximum can reach 41°C (106°F) and the minimum can be as low as 17°C (63°F). Travelers should prepare for warm weather and stay hydrated while enjoying the diverse activities this destination offers.

August Weather in Helena: Daily Temperature Highs, Lows, and Averages

The chart illustrates August temperature patterns in Helena, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Helena, August typically has an average temperature of 28°C (82°F), with highs reaching up to 41°C (106°F) and lows dropping to around 17°C (63°F).
JanFebMarAprMayJunJulAugSepOctNovDec525761677580838279725854
Data source: Temperature data for Helena 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.

August Precipitation in Helena

In Helena in August, the precipitation amount is 106 mm (4.2 in), occurring over 18 days.

August Precipitation Trends in Helena

The chart displays monthly precipitation patterns in Helena, with values for each month alongside August’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how August’s conditions compare to those of other months. In Helena, August typically receives around 106 mm (4.2 inches) of precipitation spread over approximately 18 days.
JanFebMarAprMayJunJulAugSepOctNovDec831077888721031181061078953126
Data source: Precipitation data for August generated using information from the Copernicus Climate Change Service.
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August Humidity in Helena

In Helena in August humidity is 79%. With an average temperature of 28°C (82°F), this humidity feels like a warm blanket wrapping around you, making outdoor exploration more strenuous and requiring frequent breaks for hydration.

August Average Humidity in Helena

This chart illustrates the average monthly humidity levels in Helena, with August’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In August, average humidity in Helena is approximately 79%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec85%82%80%76%73%74%80%79%83%77%84%88%
Data source: Humidity data for August generated using information from the Copernicus Climate Change Service.

August UV Index in Helena

In Helena in August, 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 Helena.

Maximum UV Index Levels in Helena for August

The chart shows the monthly maximum UV Index (UVI) for Helena in August, 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 August, the maximum UV index in Helena typically reaches 11, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec479101111111110864
Data source: Helena August 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 August Weather in Helena Compares to Other Months

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

This table compares monthly weather conditions in Helena, showing how August’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather11°C (52°F)83 mm (3.2 inches)85%moderate
February Weather14°C (58°F)107 mm (4.2 inches)82%high
March Weather16°C (62°F)78 mm (3.1 inches)80%very high
April Weather20°C (67°F)88 mm (3.4 inches)76%very high
May Weather24°C (76°F)72 mm (2.8 inches)73%extreme
June Weather27°C (80°F)103 mm (4.1 inches)74%extreme
July Weather28°C (83°F)118 mm (4.6 inches)80%extreme
August Weather28°C (82°F)106 mm (4.2 inches)79%extreme
September Weather26°C (80°F)107 mm (4.2 inches)83%very high
October Weather22°C (72°F)89 mm (3.5 inches)77%very high
November Weather14°C (58°F)53 mm (2.1 inches)84%high
December Weather12°C (54°F)126 mm (4.9 inches)88%moderate

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