Helena
Montana, USA
Long-term weather forecast
Long-term weather forecast

August weather forecast and climate
Helena, MT

The State Capital building of Montana in Helena city, set on a beautiful natural park
The State Capital building of Montana in Helena city, set on a beautiful natural park
August, the last month of the summer, in Helena, is another warm month, with temperature in the range of an average high of 84.6°F (29.2°C) and an average low of 52.2°F (11.2°C).

Temperature

In Helena, the average high-temperature in August is essentially the same as in July - a still moderately hot 84.6°F (29.2°C). The average low-temperature, in August, is 52.2°F (11.2°C).

Heat index

In August, the average heat index is appraised at 85.3°F (29.6°C). Constant exposure and activity lead to possible fatigue. Prolonged exercise may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With the exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'apparent temperature', 'real feel', or 'feels like', combines air temperature and relative humidity to represent a human perceived temperature equivalent. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (clothing, differences in body mass, height, and shape, wind). Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.

Humidity

The average relative humidity is 47.5%.

Rainfall

In August, the rain falls for 7.3 days. Throughout August, 1.2" (30.5mm) of precipitation is accumulated. Throughout the year, there are 91.6 rainfall days, and 11.2" (284.9mm) of precipitation is accumulated.

Snowfall

January through May, August through December are months with snowfall in Helena. August is the first month it typically snows. Throughout August, in the average 0.1 snowfall days, it receives 0.3" (7.6mm) of snow. In Helena, during the entire year, snow falls for 32.8 days, and aggregates up to 38.1" (967.8mm) of snow.

Daylight

In August, the average length of the day is 14.1h.

Sunshine

The average sunshine in Helena is 10.5h.

UV index

In Helena, Montana, the average daily maximum UV index is 8. A UV Index value of 8 to 10 symbolizes a very high threat to health from the exposure to the Sun's UV radiation for ordinary individuals.
Note: In August, the average maximum UV index of 8 translate into the following recommendations:
Take extra precautions. Protection against sun damage is required. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun. Beware! The strength of the UV rays is increased nearly double-fold by the reflection of the snow.

What is the temperature in August in Helena?

The average high-temperature, in August, is 84.6°F (29.2°C), while the average low-temperature is 52.2°F (11.2°C). In August, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), that combines relative humidity and air temperature, is evaluated at 85.3°F (29.6°C).

What is the average humidity in August in Helena?

In August, the average relative humidity is 47.5%.

How many days does it rain in August in Helena?

In Helena, in August, during 7.3 rainfall days, 1.2" (30.5mm) of precipitation is typically accumulated.

When does it start to snow in Helena?

August is the first month it typically snows. Throughout August, in the average 0.1 snowfall days, it receives 0.3" (7.6mm) of snow.

How many hours of daylight does Helena have in August?

In Helena, the average length of the day in August is 14.1h.

How long on average sun shines in August in Helena?

In Helena, Montana, the average sunshine in August is 10.5h.

What is the UV index reading in August in Helena?

In Helena, Montana, the average daily maximum UV index in August is 8. A UV Index estimate of 8 to 10 represents a very high health vulnerability from the exposure to the Sun's UV rays.
Average temperature in August - Helena, MT
  • Average high temperature in August: 29.2°C

The warmest month (with the highest average high temperature) is July (29.8°C).
The month with the lowest average high temperature is December (-0.2°C).

  • Average low temperature in August: 11.2°C

The month with the highest average low temperature is July (12.4°C).
The coldest month (with the lowest average low temperature) is December (-11.2°C).

Average humidity in August - Helena, MT
  • Average humidity in August: 47.5%

The month with the highest relative humidity is December (68.1%).
The month with the lowest relative humidity is July (46.4%).

Average rainfall in August - Helena, MT
  • Average rainfall in August: 30.5mm

The wettest month (with the highest rainfall) is June (52.3mm).
The driest month (with the lowest rainfall) is February (7.6mm).

Average rainfall days in August - Helena, MT
  • Average rainfall days in August: 7.3 days

The month with the highest number of rainy days is June (11.2 days).
The month with the lowest number of rainy days is February (5.9 days).

Average snowfall in August - Helena, MT
  • Average snowfall in August: 7.6mm

The month with the highest snowfall is December (185.4mm).
Months with the lowest snowfall are June and July (0mm).

Average snowfall days in August - Helena, MT
  • Average snowfall days in August: 0.1 days

The month with the highest number of snowfall days is December (6 days).
The month with the lowest number of snowfall days is July (0 days).

Average daylight in August / Average sunshine in August - Helena, MT
  • Average daylight in August: 14.1h

The month with the longest days is June (Average daylight: 15.8h).
The month with shortest days is December (Average daylight: 8.6h).

  • Average sunshine in August: 10.5h

The month with most sunshine is July (Average sunshine: 11.9h).
The month with least sunshine is December (Average sunshine: 3.2h).

Average UV index in August - Helena, MT
  • Average UV index in August: 8

The month with the highest UV index is July (UV index 9).
Months with the lowest UV index are January, November and December (UV index 1).