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
May's onset is marked by a temperature increase, moving from a refreshing 66°F (18.9°C) in April to a warm 75.4°F (24.1°C). During the nights in May, an average low-temperature of 58.1°F (14.5°C) is observed.Humidity
May is the most humid month, with an average relative humidity of 79%.Rainfall
In Saint Johns, during May, the rain falls for 17 days and regularly aggregates up to 3.27" (83mm) of precipitation. Throughout the year, there are 147.6 rainfall days, and 29.17" (741mm) of precipitation is accumulated.Snowfall
In Saint Johns, snow does not fall in May through October.Daylight
In Saint Johns, the average length of the day in May is 14h and 15min.On the first day of May, sunrise is at 5:59 am and sunset at 7:48 pm. On the last day of the month, sunrise is at 5:35 am and sunset at 8:13 pm CDT.
Sunshine
In Saint Johns, the average sunshine in May is 9.2h.UV index
In Saint Johns, the average daily maximum UV index in May is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: A maximum high UV index of 5 in May translates into the following recommendations:
Make use of precautions - It is urged to ward off sun damage. Being in direct Sun during midday can be harmful due to intense solar radiation; take precautions. A hat with a generous brim can prevent nearly 50% of UV rays from reaching your eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the average May temperature?
What is the most humid month?
What is the average humidity in May?
How much does it rain in May?
When it does not snow?
Does it snow in May?
What is the average length of the day in May?
When are sunrise and sunset in May?
How long on average sun shines in May?
What is the UV index reading in May in Saint Johns?
Average temperature in May
Saint Johns, IL
- Average high temperature in May: 75.4°F
The warmest month (with the highest average high temperature) is July (87.3°F).
The month with the lowest average high temperature is January (38.8°F).
- Average low temperature in May: 58.1°F
The month with the highest average low temperature is July (68.7°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).
Average pressure in May
Saint Johns, IL
- 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 (29.93"Hg).
Average wind speed in May
Saint Johns, IL
- Average wind speed in May: 7.8mph
The windiest months (with the highest average wind speed) are January and February (9.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).
Average humidity in May
Saint Johns, IL
- Average humidity in May: 79%
The month with the highest relative humidity is May (79%).
The month with the lowest relative humidity is October (71%).
Average rainfall in May
Saint Johns, IL
- Average rainfall in May: 3.27"
The wettest month (with the highest rainfall) is April (3.58").
The driest month (with the least rainfall) is January (1.5").
Average rainfall days in May
Saint Johns, IL
- Average rainfall days in May: 17 days
The month with the highest number of rainy days is May (17 days).
The month with the least rainy days is December (8.2 days).
Average snowfall in May
Saint Johns, IL
- Average snowfall in May: 0"
The month with the highest snowfall is February (1.5").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in May
Saint Johns, IL
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (5.4 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
Saint Johns, IL
- Average daylight in May: 14h and 1min
The month with the longest days is June (Average daylight: 14h and 48min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in May: 9h and 1min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in May
Saint Johns, IL
- Average sunshine days in May: 11.4 days
The months with the most sunshine days are October and November (19.5 days).
The month with the least sunshine days is May (11.4 days).
Average UV index in May
Saint Johns, IL
- Average UV index in May: 5
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in May
Saint Johns, IL
- Average cloud cover in May: 39
The months with the most cloud cover are January and February (Cloud cover 50).
The month with the least cloud cover is June (Cloud cover 28).
Average visibility in May
Saint Johns, IL
- 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).
Saint Johns, Illinois, USA
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