May weather forecastHerrin, IL
May
Weather in May
May, the last month of the spring in Herrin, is a moderately hot month, with temperature in the range of an average high of 75.4°F (24.1°C) and an average low of 58.1°F (14.5°C).Temperature
May's onset brings a rise in the average high-temperature, moving from an enjoyable 66.4°F (19.1°C) in April to a warm 75.4°F (24.1°C). During May, the average low-temperature is recorded at a mild 58.1°F (14.5°C).Humidity
May is the most humid month, with an average relative humidity of 79%.Rainfall
In Herrin, Illinois, during May, the rain falls for 15.1 days and regularly aggregates up to 2.52" (64mm) of precipitation. Throughout the year, in Herrin, Illinois, there are 137.6 rainfall days, and 23.03" (585mm) of precipitation is accumulated.Snowfall
May through September are months without snowfall in Herrin.Daylight
In Herrin, Illinois, the average length of the day in May is 14h and 14min.On the first day of May in Herrin, sunrise is at 5:59 am and sunset at 7:47 pm. On the last day of the month, sunrise is at 5:35 am and sunset at 8:12 pm CDT.
Sunshine
In Herrin, Illinois, the average sunshine in May is 9.2h.UV index
The months with the highest UV index in Herrin are May through August, with an average maximum UV index of 6. A UV Index of 6 to 7 symbolizes a high health vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 6 during May leads to these instructions:
Implement preventive steps and embrace sun safety standards. Protection from skin and eye distress is compulsory. Stay in the shade and avoid direct Sun exposure from 10 a.m. to 4 p.m., a period when UV radiation is particularly strong, noting that parasols or canopies may not offer total sun protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in May
Herrin, IL
- Average high temperature in May: 75.4°F
The warmest month (with the highest average high temperature) is July (87.4°F).
The month with the lowest average high temperature is January (39.6°F).
- Average low temperature in May: 58.1°F
The month with the highest average low temperature is July (68.5°F).
The coldest month (with the lowest average low temperature) is January (26.1°F).
Average pressure in May
Herrin, IL
- Average pressure in May: 29.97"Hg
The month with the highest atmospheric pressure is January (30.16"Hg).
The month with the lowest atmospheric pressure is June (29.94"Hg).
Average wind speed in May
Herrin, IL
- Average wind speed in May: 7.6mph
The windiest months (with the highest average wind speed) are January and February (9.4mph).
The calmest months (with the lowest average wind speed) are July and August (5.8mph).
Average humidity in May
Herrin, 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
Herrin, IL
- Average rainfall in May: 2.52"
The wettest month (with the highest rainfall) is April (3.11").
The driest month (with the least rainfall) is September (1.1").
Average rainfall days in May
Herrin, IL
- Average rainfall days in May: 15.1 days
The month with the highest number of rainy days is July (15.3 days).
The month with the least rainy days is November (7.8 days).
Average snowfall in May
Herrin, IL
- Average snowfall in May: 0"
The months with the highest snowfall are January and February (0.94").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in May
Herrin, IL
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is February (4.3 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
Herrin, IL
- Average daylight in May: 14h and 12min
The month with the longest days is June (Average daylight: 14h and 42min).
The month with the shortest days is December (Average daylight: 9h and 36min).
- Average sunshine in May: 9h and 12min
The months with the most sunshine are June and July (Average sunshine: 10h and 30min).
The month with the least sunshine is January (Average sunshine: 4h and 36min).
Average sunshine days in May
Herrin, IL
- Average sunshine days in May: 13.3 days
The month with the most sunshine days is October (20.6 days).
The month with the least sunshine days is July (12.9 days).
Average UV index in May
Herrin, IL
- Average UV index in May: 6
The months with the highest UV index are May, June, July and August (UV index 6).
The months with the lowest UV index are January, February and December (UV index 2).
Average cloud cover in May
Herrin, IL
- Average cloud cover in May: 39
The month with the most cloud cover is February (Cloud cover 51).
The months with the least cloud cover are June, August and September (Cloud cover 28).
Average visibility in May
Herrin, 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).





