May weather forecastRoy, MT
May
Weather in May
May, the last month of the spring in Roy, is a mild month, with an average temperature ranging between max 58.5°F (14.7°C) and min 40.1°F (4.5°C).Temperature
May's arrival coincides with a rise in the average high-temperature, moving from April's frosty 47.8°F (8.8°C) to a refreshing 58.5°F (14.7°C). An average low-temperature of 40.1°F (4.5°C) is recorded during the nights in May in Roy, Montana.Humidity
In Roy, the average relative humidity in May is 65%.Rainfall
The month with the most rainfall is May, when the rain falls for 19.3 days and typically aggregates up to 3.39" (86mm) of precipitation.Snowfall
January through June, September through December are months with snowfall in Roy. In Roy, in May, snow falls for 2.4 days, with typically accumulated 2.48" (63mm) of snow. Throughout the year, there are 83.4 snowfall days, and 45.51" (1156mm) of snow is accumulated.Daylight
In May, the average length of the day in Roy is 15h and 8min.On the first day of May in Roy, sunrise is at 5:57 am and sunset at 8:27 pm. On the last day of the month, sunrise is at 5:23 am and sunset at 9:04 pm MDT.
Sunshine
In Roy, the average sunshine in May is 10h.UV index
In Roy, the average daily maximum UV index in May is 4. A UV Index estimate of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: In May, a daily maximum UV index of 4 leads to the following instructions:
Act with care - Obligation to protect against skin and eye damage is highlighted. It's recommended to limit sun exposure when its radiation is at its peak during midday. During bright days, sunglasses that offer UVA and UVB defense are recommended. Be watchful! The reflection of snow can enhance the intensity of the Sun's UV radiation nearly double.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Roy, MT
- Average high temperature in May: 58.5°F
The warmest month (with the highest average high temperature) is July (78.8°F).
The months with the lowest average high temperature are February and December (29.1°F).
- Average low temperature in May: 40.1°F
The month with the highest average low temperature is August (54.5°F).
The coldest month (with the lowest average low temperature) is February (15.3°F).
Average pressure in May
Roy, MT
- Average pressure in May: 29.92"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in May
Roy, MT
- Average wind speed in May: 8.8mph
The windiest months (with the highest average wind speed) are January, April and October (9.9mph).
The calmest month (with the lowest average wind speed) is August (7.4mph).
Average humidity in May
Roy, MT
- Average humidity in May: 65%
The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is August (47%).
Average rainfall in May
Roy, MT
- Average rainfall in May: 3.39"
The wettest month (with the highest rainfall) is May (3.39").
The driest month (with the least rainfall) is December (0.71").
Average rainfall days in May
Roy, MT
- Average rainfall days in May: 19.3 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 May
Roy, MT
- Average snowfall in May: 2.48"
The month with the highest snowfall is April (9.13").
The months with the least snowfall are July and August (0").
Average snowfall days in May
Roy, MT
- Average snowfall days in May: 2.4 days
The month with the highest number of snowfall days is February (15.2 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in May /
Average sunshine in May
Roy, MT
- Average daylight in May: 15h and 6min
The month with the longest days is June (Average daylight: 15h and 54min).
The month with the shortest days is December (Average daylight: 8h and 30min).
- Average sunshine in May: 10h and 0min
The month with the most sunshine is July (Average sunshine: 11h and 48min).
The month with the least sunshine is February (Average sunshine: 5h and 30min).
Average sunshine days in May
Roy, MT
- Average sunshine days in May: 8.9 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 May
Roy, 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, March, April, October, November and December (UV index 2).
Average cloud cover in May
Roy, MT
- Average cloud cover in May: 36
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 May
Roy, MT
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
