August Weather in Helena, United States

Last updated: June 24, 2025

In August, the average temperature in Helena, United States hovers around 27°C (81°F). Daily highs can soar to a warm 35°C (95°F), while lows might dip to a cooler 17°C (63°F). Expect about 114 mm (4.5 in) of precipitation spread over 12 days, contributing to an average humidity level of 74%. Stay prepared for a mix of warmth and moisture!

August Temperature in Helena

In August in Helena, the average temperature is 27°C (81°F). Maximums can reach 35°C (95°F), and minimums can be as low as 17°C (63°F). This pleasant weather makes Helena an ideal destination for travelers seeking warm and comfortable conditions.

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 27°C (81°F), with highs reaching up to 35°C (95°F) and lows dropping to around 17°C (63°F).

Data source: Temperature data for Helena generated using information from the Copernicus Climate Change Service.

August Precipitation in Helena

In Helena in August, the precipitation amount is 114 mm (4.5 in) spread over 12 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 114 mm (4.5 inches) of precipitation spread over approximately 12 days.

Data source: Precipitation data for August generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

August Humidity in Helena

In Helena in August humidity is 74%. With an average temperature of 27°C (81°F), this humidity feels like a warm, enveloping blanket, making traveling feel both sticky and draining, yet the heat invites you to seek out refreshing dips in pools or shady spots to relax.

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 74%, offering insight into how humid the weather typically is during this month.

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 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 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 10, which falls under the very high exposure category.

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.
	Temperature	Precipitation	Humidity	UV
January Weather	7°C (44°F)	107 mm (4.2 inches)	84%	moderate
February Weather	9°C (48°F)	185 mm (7.3 inches)	83%	high
March Weather	14°C (57°F)	172 mm (6.8 inches)	81%	very high
April Weather	17°C (62°F)	146 mm (5.7 inches)	81%	very high
May Weather	23°C (73°F)	138 mm (5.5 inches)	83%	extreme
June Weather	26°C (79°F)	133 mm (5.2 inches)	83%	extreme
July Weather	28°C (82°F)	124 mm (4.9 inches)	81%	extreme
August Weather	27°C (81°F)	114 mm (4.5 inches)	74%	very high
September Weather	25°C (77°F)	92 mm (3.6 inches)	71%	very high
October Weather	19°C (66°F)	111 mm (4.4 inches)	76%	high
November Weather	11°C (52°F)	82 mm (3.2 inches)	84%	high
December Weather	9°C (49°F)	144 mm (5.7 inches)	88%	moderate