May weather forecast
Halfmoon, MT

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Weather in May

The last month of the spring, May, is a refreshing month in Halfmoon, Montana, with temperature in the range of an average low of 35.2°F (1.8°C) and an average high of 59.5°F (15.3°C).

Temperature

With the onset of May, Halfmoon's average high-temperature experiences a rise, moving from April's chilly 46.6°F (8.1°C) to a moderate 59.5°F (15.3°C). Halfmoon, in May, displays a significant temperature downturn during the night, with an average reading of 35.2°F (1.8°C).

Humidity

The average relative humidity in May is 68%.

Rainfall

In Halfmoon, in May, during 13.8 rainfall days, 1.1" (28mm) of precipitation is typically accumulated. In Halfmoon, during the entire year, the rain falls for 126.4 days and collects up to 11.22" (285mm) of precipitation.

Snowfall

Months with snowfall are January through May, September through December. May is the last month it regularly snows. During 1.5 snowfall days, in May, Halfmoon aggregates 0.55" (14mm) of snow. In Halfmoon, during the entire year, snow falls for 97 days and aggregates up to 33.86" (860mm) of snow.

Daylight

In May, the average length of the day is 15h and 15min.
On the first day of the month, sunrise is at 6:16 am and sunset at 8:51 pm. On the last day of May, in Halfmoon, sunrise is at 5:39 am and sunset at 9:29 pm MDT.

Sunshine

In Halfmoon, the average sunshine in May is 10.4h.

UV index

In Halfmoon, the average daily maximum UV index in May is 4. A UV Index reading of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for average individuals.
Note: The UV index of 4 in May translates into these instructions:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. Limiting sun exposure during midday hours helps in reducing the harmful effects of UV radiation. Sunglasses providing both UVA and UVB protection are non-negotiable on sunlit days. Be advised! The UV radiation from the Sun can be almost doubled due to the reflective properties of snow.

Frequently asked questions

What are the temperatures in May?

In Halfmoon, 59.5°F (15.3°C) is the average high-temperature and 35.2°F (1.8°C) is the average low-temperature during May.

What is the average humidity in May?

The average relative humidity in May in Halfmoon, Montana, is 68%.

How much does it rain in Halfmoon in May?

In Halfmoon, during May, the rain falls for 13.8 days and regularly aggregates up to 1.1" (28mm) of precipitation.

What is the last month it snows?

May is the last month it regularly snows. During 1.5 snowfall days, in May, Halfmoon aggregates 0.55" (14mm) of snow.

How many hours of daylight does Halfmoon have in May?

In May, the average day length is 15h and 15min.

What time are sunrise and sunset in May in Halfmoon?

On the first day of May, sunrise is at 6:16 am and sunset at 8:51 pm. On the last day of the month, sunrise is at 5:39 am and sunset at 9:29 pm MDT.

How many hours of sunshine does Halfmoon have in May?

The average sunshine duration in May in Halfmoon is 10.4h.

How high is the UV index in May?

The average daily maximum UV index in May is 4. A UV Index of 3 to 5 symbolizes a medium hazard to health from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in May
Halfmoon, MT

Average temperature in May - Halfmoon, MT
  • Average high temperature in May: 59.5°F

The warmest month (with the highest average high temperature) is July (77.9°F).
The month with the lowest average high temperature is December (25.7°F).

  • Average low temperature in May: 35.2°F

The month with the highest average low temperature is August (45.5°F).
The coldest month (with the lowest average low temperature) is February (13.5°F).

Average pressure in May
Halfmoon, MT

Average pressure in May - Halfmoon, MT
  • Average pressure in May: 29.96"Hg

The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).

Average wind speed in May
Halfmoon, MT

Average wind speed in May - Halfmoon, MT
  • Average wind speed in May: 4.4mph

The windiest month (with the highest average wind speed) is April (4.6mph).
The calmest months (with the lowest average wind speed) are August and December (3.7mph).

Average humidity in May
Halfmoon, MT

Average humidity in May - Halfmoon, MT
  • Average humidity in May: 68%

The month with the highest relative humidity is January (93%).
The month with the lowest relative humidity is August (55%).

Average rainfall in May
Halfmoon, MT

Average rainfall in May - Halfmoon, MT
  • Average rainfall in May: 1.1"

The wettest month (with the highest rainfall) is June (1.42").
The driest month (with the least rainfall) is August (0.43").

Average rainfall days in May
Halfmoon, MT

Average rainfall days in May - Halfmoon, MT
  • Average rainfall days in May: 13.8 days

The month with the highest number of rainy days is April (15.8 days).
The month with the least rainy days is August (6.3 days).

Average snowfall in May
Halfmoon, MT

Average snowfall in May - Halfmoon, MT
  • Average snowfall in May: 0.55"

The month with the highest snowfall is January (7.72").
The months with the least snowfall are June, July and August (0").

Average snowfall days in May
Halfmoon, MT

Average snowfall days in May - Halfmoon, MT
  • Average snowfall days in May: 1.5 days

The month with the highest number of snowfall days is December (19.1 days).
The months with the least snowfall days are July and August (0 days).

Average daylight in May /
Average sunshine in May
Halfmoon, MT

Average daylight in May / Average sunshine in May - Halfmoon, MT
  • Average daylight in May: 15h and 1min

The month with the longest days is June (Average daylight: 16h and 0min).
The month with the shortest days is December (Average daylight: 8h and 24min).

  • Average sunshine in May: 10h and 2min

The month with the most sunshine is July (Average sunshine: 11h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 30min).

Average sunshine days in May
Halfmoon, MT

Average sunshine days in May - Halfmoon, MT
  • Average sunshine days in May: 14.2 days

The month with the most sunshine days is July (21.5 days).
The month with the least sunshine days is March (7.7 days).

Average UV index in May
Halfmoon, MT

Average UV index in May - Halfmoon, MT
  • Average UV index in May: 4

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).

Average cloud cover in May
Halfmoon, MT

Average cloud cover in May - Halfmoon, MT
  • Average cloud cover in May: 33

The month with the most cloud cover is January (Cloud cover 65).
The months with the least cloud cover are July and August (Cloud cover 15).

Average visibility in May
Halfmoon, MT

Average visibility in May - Halfmoon, MT
  • Average visibility in May: 6mi

The months with the highest visibility are May, June, July, August, September and October (6mi).
The month with the lowest visibility is January (3mi).

Halfmoon, Montana, USA

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