Contents
- Weather in May
- Frequently asked questions
- Average temperature in May
- Average pressure in May
- Average wind speed in May
- Average humidity in May
- Average rainfall in May
- Average rainfall days in May
- Average snowfall in May
- Average snowfall days in May
- Average daylight in May
- Average sunshine in May
- Average sunshine days in May
- Average UV index in May
- Average cloud cover in May
- Average visibility in May
Weather in May
Temperature
The arrival of May brings a change in Alton's weather, with average high-temperatures moving from April's chilly 44.2°F (6.8°C) to a moderate 56.3°F (13.5°C). Alton reports a considerable drop from daytime temperatures in May, recording an average nighttime figure of 33.3°F (0.7°C).Humidity
In Alton, Idaho, the average relative humidity in May is 66%.Rainfall
The month with the most rainfall is May, when the rain falls for 17.3 days and typically aggregates up to 2.6" (66mm) of precipitation.Snowfall
Months with snowfall are January through June, September through December. In Alton, in May, snow falls for 3.4 days, with typically accumulated 2.56" (65mm) of snow. In Alton, during the entire year, snow falls for 116.1 days and aggregates up to 91.14" (2315mm) of snow.Daylight
In May, the average length of the day in Alton is 14h and 37min.On the first day of May, sunrise is at 6:18 am and sunset at 8:24 pm. On the last day of the month, sunrise is at 5:50 am and sunset at 8:54 pm MDT.
Sunshine
The average sunshine in May is 10.4h.UV index
In May, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: In May, a daily UV index of 4 turns into the following recommendations:
Take necessary precautions - Suggestions to elude sunburn are provided. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses. Notice this! Nearly double the intensity of the Sun's UV radiation can be caused by snow reflection.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in May?
What is the average humidity in May?
What is the wettest month?
How many days does it rain in May?
How many days does it snow in May?
How many hours of daylight does Alton have in May?
When are sunrise and sunset in May?
How many hours of sunshine does Alton have in May?
What is the UV index reading in May?
Average temperature in May
Alton, ID
- Average high temperature in May: 56.3°F
The warmest month (with the highest average high temperature) is July (79°F).
The month with the lowest average high temperature is December (25.2°F).
- Average low temperature in May: 33.3°F
The month with the highest average low temperature is July (48.9°F).
The coldest month (with the lowest average low temperature) is January (7.9°F).
Average pressure in May
Alton, ID
- Average pressure in May: 29.91"Hg
The month with the highest atmospheric pressure is January (30.29"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).
Average wind speed in May
Alton, ID
- Average wind speed in May: 5.5mph
The windiest month (with the highest average wind speed) is June (5.8mph).
The calmest months (with the lowest average wind speed) are January and December (4.2mph).
Average humidity in May
Alton, ID
- Average humidity in May: 66%
The months with the highest relative humidity are January and February (92%).
The month with the lowest relative humidity is August (42%).
Average rainfall in May
Alton, ID
- Average rainfall in May: 2.6"
The wettest month (with the highest rainfall) is May (2.6").
The driest month (with the least rainfall) is July (0.63").
Average rainfall days in May
Alton, ID
- Average rainfall days in May: 17.3 days
The month with the highest number of rainy days is May (17.3 days).
The month with the least rainy days is January (6 days).
Average snowfall in May
Alton, ID
- Average snowfall in May: 2.56"
The month with the highest snowfall is February (18.39").
The months with the least snowfall are July and August (0").
Average snowfall days in May
Alton, ID
- Average snowfall days in May: 3.4 days
The month with the highest number of snowfall days is December (21.6 days).
The months with the least snowfall days are July and August (0 days).
Average daylight in May /
Average sunshine in May
Alton, ID
- Average daylight in May: 14h and 4min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- 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: 4h and 24min).
Average sunshine days in May
Alton, ID
- Average sunshine days in May: 8.8 days
The month with the most sunshine days is July (18.8 days).
The month with the least sunshine days is February (6.8 days).
Average UV index in May
Alton, ID
- Average UV index in May: 4
The months with the highest UV index are June and July (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover in May
Alton, ID
- Average cloud cover in May: 30
The month with the most cloud cover is February (Cloud cover 62).
The months with the least cloud cover are July and August (Cloud cover 12).
Average visibility in May
Alton, ID
- Average visibility in May: 6mi
The months with the highest visibility are May, June, July, August, September and October (6mi).
The months with the lowest visibility are January and February (3mi).
Alton, Idaho, USA
Weather forecast for your location
2. Allow the app to use your location