August weather forecast and climate
Roy, MT

August, the last month of the summer, in Roy, is also a moderately hot month, with average temperature varying between 54.5°F (12.5°C) and 78.1°F (25.6°C).

Temperature

In Roy, Montana, the average high-temperature is practically the same as in July - a still moderately hot 78.1°F (25.6°C). The average low-temperature, in Roy, Montana, is 54.5°F (12.5°C).

Humidity

With an average relative humidity of 47%, August is the least humid month in Roy, Montana.

Rainfall

In Roy, during August, the rain falls for 10.5 days and regularly aggregates up to 1.34" (34mm) of precipitation. Throughout the year, there are 126.2 rainfall days, and 17.83" (453mm) of precipitation is accumulated.

Snowfall

July and August are months without snowfall in Roy.

Daylight

The average length of the day in Roy is 14.2h.

Sunshine

In Roy, the average sunshine in August is 11.4h.

UV index

The average daily maximum UV index in August is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from unsafe exposure to the UV radiation for the ordinary person.
Note: In August, the average maximum UV index of 5 translate into the following recommendations:
Take precautions - Protection against sun damage is advised. The Sun's most intense and consequently most harmful UV radiation during midday hours should be decreased by minimizing exposure and seeking shade. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.

What is the temperature in August in Roy?

The average high-temperature, in August, in Roy, is 78.1°F (25.6°C), while the average low-temperature is 54.5°F (12.5°C).

What is the least humid month in Roy?

With an average relative humidity of 47%, August is the least humid month.

What is the average humidity in August in Roy?

The average relative humidity in August is 47%.

How much does it rain in Roy in August?

In Roy, in August, during 10.5 rainfall days, 1.34" (34mm) of precipitation is typically accumulated.

Does it snow in Roy in August?

In Roy, Montana, in August, it doesn't snow. In September, it regularly snows.

When it does not snow in Roy?

July and August are months without snowfall in Roy.

How many hours of daylight does Roy have in August?

In August, the average length of the day in Roy, Montana, is 14.2h.

How many hours of sunshine does Roy have in August?

In August, the average sunshine is 11.4h.

How high is the UV index in August in Roy?

The average daily maximum UV index in August in Roy is 5. A UV Index estimate of 3 to 5 represents a moderate health threat from unsafe exposure to the Sun's UV rays.
Average temperature in August - Roy, MT
  • Average high temperature in August: 25.6°C

The warmest month (with the highest average high temperature) is July (26°C).
Months with the lowest average high temperature are February and December (-1.6°C).

  • Average low temperature in August: 12.5°C

The month with the highest average low temperature is August (12.5°C).
The coldest month (with the lowest average low temperature) is February (-9.3°C).

Average pressure in August - Roy, MT
  • Average pressure in August: 1012.4mbar

The month with the highest atmospheric pressure is January (1020.3mbar).
The month with the lowest atmospheric pressure is June (1010.9mbar).

Average wind speed in August - Roy, MT
  • Average wind speed in August: 11.9km/h

The windiest months (with the highest average wind speed) are January, April and October (15.9km/h).
The calmest month (with the lowest average wind speed) is August (11.9km/h).

Average humidity in August - Roy, MT
  • Average humidity in August: 47%

The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is August (47%).

Average rainfall in August - Roy, MT
  • Average rainfall in August: 34mm

The wettest month (with the highest rainfall) is May (86mm).
The driest month (with the least rainfall) is December (18mm).

Average rainfall days in August - Roy, MT
  • Average rainfall days in August: 10.5 days

The month with the highest number of rainy days is May (19.3 days).
The month with the least rainy days is January (5.4 days).

Average snowfall in August - Roy, MT
  • Average snowfall in August: 0mm

The month with the highest snowfall is April (232mm).
Months with the least snowfall are July and August (0mm).

Average snowfall days in August - Roy, MT
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is February (15.2 days).
Months with the least snowfall days are July and August (0 days).

Average daylight in August / Average sunshine in August - Roy, MT
  • Average daylight in August: 14.2h

The month with the longest days is June (Average daylight: 15.9h).
The month with the shortest days is December (Average daylight: 8.5h).

  • Average sunshine in August: 11.4h

The month with the most sunshine is July (Average sunshine: 11.8h).
The month with the least sunshine is February (Average sunshine: 5.5h).

Average sunshine days in August - Roy, MT
  • Average sunshine days in August: 17.2 days

The month with the most sunshine days is September (19.3 days).
The month with the least sunshine days is April (8.3 days).

Average UV index in August - Roy, MT
  • Average UV index in August: 5

The month with the highest UV index is July (UV index 6).
Months with the lowest UV index are January, February, March, April, October, November and December (UV index 2).

Average cloud cover in August - Roy, MT
  • Average cloud cover in August: 17

The month with the most cloud cover is February (Cloud cover 45).
The month with the least cloud cover is July (Cloud cover 16).

Average visibility in August - Roy, MT
  • Average visibility in August: 10km

Months with the highest visibility are June, July, August and September (10km).
Months with the lowest visibility are January, February, March, April, May, October, November and December (9km).