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
With the onset of May, Rock Falls's weather sees a temperature rise, transitioning from a moderate 57.9°F (14.4°C) in April to a pleasant 69.4°F (20.8°C). During the nights in May, the temperature averages to a cool 52.5°F (11.4°C).Humidity
The average relative humidity in May is 77%.Rainfall
May is the month with the most rainfall. Rain falls for 17.3 days and accumulates 2.83" (72mm) of precipitation.Snowfall
In Rock Falls, snow does not fall in May through September.Daylight
In Rock Falls, the average length of the day in May is 14h and 34min.On the first day of May, sunrise is at 5:53 am and sunset at 7:57 pm. On the last day of the month, sunrise is at 5:26 am and sunset at 8:26 pm CDT.
Sunshine
In May, the average sunshine is 8.6h.UV index
In May, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for the ordinary person.Note: In May, the maximum UV index of 5 suggests these recommendations:
Preventative actions are necessary - Recommendations to ward off sunburn are given. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. During bright days, sunglasses that offer UVA and UVB defense are recommended.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What are May temperatures?
What is the average humidity in May?
What is the rainiest month?
How much does it rain in May?
When it does not snow?
Does it snow in May?
How many hours of daylight does Rock Falls have in May?
When are sunrise and sunset in May?
How many hours of sunshine does Rock Falls have in May?
How high is the UV index in May?
Average temperature in May
Rock Falls, IL
- Average high temperature in May: 69.4°F
The warmest month (with the highest average high temperature) is July (80.2°F).
The month with the lowest average high temperature is January (27.7°F).
- Average low temperature in May: 52.5°F
The month with the highest average low temperature is July (63.9°F).
The coldest month (with the lowest average low temperature) is January (14.9°F).
Average pressure in May
Rock Falls, IL
- Average pressure in May: 29.95"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed in May
Rock Falls, IL
- Average wind speed in May: 8.8mph
The windiest month (with the highest average wind speed) is April (10.4mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity in May
Rock Falls, IL
- Average humidity in May: 77%
The months with the highest relative humidity are January and July (85%).
The month with the lowest relative humidity is October (73%).
Average rainfall in May
Rock Falls, IL
- Average rainfall in May: 2.83"
The wettest month (with the highest rainfall) is May (2.83").
The driest months (with the least rainfall) are January and February (0.75").
Average rainfall days in May
Rock Falls, IL
- 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 (4.8 days).
Average snowfall in May
Rock Falls, IL
- Average snowfall in May: 0"
The month with the highest snowfall is January (2.56").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days in May
Rock Falls, IL
- Average snowfall days in May: 0 days
The month with the highest number of snowfall days is January (10.2 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
Rock Falls, IL
- 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: 8h and 4min
The month with the most sunshine is July (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 48min).
Average sunshine days in May
Rock Falls, IL
- Average sunshine days in May: 11.4 days
The months with the most sunshine days are November and December (18.8 days).
The month with the least sunshine days is June (11.3 days).
Average UV index in May
Rock Falls, IL
- Average UV index in May: 5
The month with the highest UV index is July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover in May
Rock Falls, IL
- Average cloud cover in May: 42
The month with the most cloud cover is January (Cloud cover 60).
The month with the least cloud cover is September (Cloud cover 31).
Average visibility in May
Rock Falls, IL
- Average visibility in May: 6mi
The months with the highest visibility are January, February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are July and August (5mi).
Rock Falls, Illinois, USA
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