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
As May arrives, Altona's weather shows an increase in high-temperatures, moving from April's refreshing 59.2°F (15.1°C) to an agreeable 70.7°F (21.5°C). Throughout May, a steady low-temperature average of 53.4°F (11.9°C) is noted.Humidity
In May, the average relative humidity is 78%.Rainfall
The month with the most rainfall is May, when the rain falls for 16.5 days and typically aggregates up to 2.76" (70mm) of precipitation.Snowfall
In Altona, snow does not fall in May through September.Daylight
In May, the average length of the day in Altona, Illinois, is 14h and 30min.On the first day of May, sunrise is at 5:57 am and sunset at 7:58 pm. On the last day of the month, sunrise is at 5:30 am and sunset at 8:26 pm CDT.
Sunshine
In Altona, the average sunshine in May is 8.9h.UV index
The average daily maximum UV index in May in Altona is 5. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unprotected exposure to Sun's UV rays for the average person.Note: A daily maximum UV index of 5 in May translates into the following instructions:
Ensure safety - Sun damage prevention is strongly urged. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. For minimizing sun-related eye damage, always choose sunglasses with UVA and UVB coverage.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are the temperatures in Altona in May?
What is the average humidity in May in Altona?
What is the rainiest month in Altona?
How many days does it rain in May in Altona?
When it does not snow in Altona?
Does it snow in Altona in May?
How many hours of daylight does Altona have in May?
When are sunrise and sunset in May in Altona?
How long on average sun shines in May in Altona?
What is the UV index reading in May in Altona?
Average temperature in May
Altona, IL
- Average high temperature in May: 70.7°F
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (28.2°F).
- Average low temperature in May: 53.4°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (16.5°F).
Average pressure in May
Altona, IL
- Average pressure in May: 29.95"Hg
The month with the highest atmospheric pressure is January (30.13"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in May
Altona, IL
- Average wind speed in May: 9.1mph
The windiest month (with the highest average wind speed) is April (10.6mph).
The calmest month (with the lowest average wind speed) is August (6.6mph).
Average humidity in May
Altona, IL
- Average humidity in May: 78%
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall in May
Altona, IL
- Average rainfall in May: 2.76"
The wettest month (with the highest rainfall) is May (2.76").
The driest month (with the least rainfall) is December (0.71").
Average rainfall days in May
Altona, IL
- Average rainfall days in May: 16.5 days
The month with the highest number of rainy days is May (16.5 days).
The month with the least rainy days is January (4 days).
Average snowfall in May
Altona, IL
- Average snowfall in May: 0"
The month with the highest snowfall is January (2.17").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in May
Altona, IL
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (10.5 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight in May /
Average sunshine in May
Altona, IL
- Average daylight in May: 14h and 3min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).
- Average sunshine in May: 8h and 5min
The months with the most sunshine are June and July (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days in May
Altona, IL
- Average sunshine days in May: 11.6 days
The month with the most sunshine days is November (19.7 days).
The month with the least sunshine days is July (11.2 days).
Average UV index in May
Altona, IL
- Average UV index in May: 5
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover in May
Altona, IL
- Average cloud cover in May: 41
The month with the most cloud cover is January (Cloud cover 57).
The month with the least cloud cover is September (Cloud cover 29).
Average visibility in May
Altona, IL
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, August, September, October, November and December (6mi).
The month with the lowest visibility is July (5mi).
Altona, Illinois, USA
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