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Contents
- Weather in January
- Weather in February
- Weather in March
- Weather in April
- Weather in May
- Weather in June
- Weather in July
- Weather in August
- Weather in September
- Weather in October
- Weather in November
- Weather in December
- Frequently asked questions
- Average temperature
- Average pressure
- Average wind speed
- Average humidity
- Average rainfall
- Average rainfall days
- Average snowfall
- Average snowfall days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
Weather in January
January, the same as December, in Rio, Illinois, is a freezing cold winter month, with an average temperature varying between 29.5°F (-1.4°C) and 17.4°F (-8.1°C). January, known for its average high temperature of 29.5°F (-1.4°C) and an average low temperature of 17.4°F (-8.1°C), is the coldest month. Weather in January »
Weather in February
The last month of the winter, February, is a cold month in Rio, Illinois, with temperature in the range of an average low of 21.2°F (-6°C) and an average high of 34.7°F (1.5°C). Rio, Illinois, observes an average high-temperature of a wintry 34.7°F (1.5°C) in February, barely different from 29.5°F (-1.4°C) in January. Weather in February »
Weather in March
March, the first month of the spring in Rio, is a chilly month, with an average temperature fluctuating between 48°F (8.9°C) and 32.9°F (0.5°C). The transition to March introduces an increase in the average high-temperature, shifting from an icy 34.7°F (1.5°C) in February to a chilly 48°F (8.9°C). Weather in March »
Weather in April
April in Rio, Illinois, is a mild spring month, with an average temperature varying between 59.9°F (15.5°C) and 43.2°F (6.2°C). April's arrival is marked by an increase in the average high-temperature, moving from a chilly 48°F (8.9°C) in March to a refreshing 59.9°F (15.5°C). Weather in April »
Weather in May
May, the last month of the spring in Rio, is a pleasant month, with an average temperature ranging between min 54°F (12.2°C) and max 70.7°F (21.5°C). As May begins, there is an increase in the average high-temperature, moving from a refreshing 59.9°F (15.5°C) in April to a pleasant 70.7°F (21.5°C). Weather in May »
Weather in June
The first month of the summer, June, is a warm month in Rio, Illinois, with an average temperature fluctuating between 79.2°F (26.2°C) and 62.4°F (16.9°C). June's arrival coincides with a subtle temperature rise, moving from May's pleasant 70.7°F (21.5°C) to a warm 79.2°F (26.2°C). Weather in June »
Weather in July
July, like June, in Rio, Illinois, is a moderately hot summer month, with an average temperature ranging between min 64.9°F (18.3°C) and max 81.1°F (27.3°C). Rio's warmest month, July, registers temperatures that range from a high of 81.1°F (27.3°C) to a low of 64.9°F (18.3°C). The heat index value for July is estimated at a tropical 87.8°F (31°C). Weather in July »
Weather in August
The last month of the summer, August, is another warm month in Rio, Illinois, with an average temperature fluctuating between 80.6°F (27°C) and 63.3°F (17.4°C). August ushers in an average high-temperature of a still moderately hot 80.6°F (27°C), aligning closely with the preceding month. Weather in August »
Weather in September
The first month of the autumn, September, is also a moderately hot month in Rio, Illinois, with temperature in the range of an average high of 75.6°F (24.2°C) and an average low of 56.3°F (13.5°C). September's average high-temperature is a still moderately hot 75.6°F (24.2°C), maintaining a close comparison with August's 80.6°F (27°C). Weather in September »
Weather in October
October, the same as September, is another refreshing autumn month in Rio, Illinois, with temperature in the range of an average low of 45.7°F (7.6°C) and an average high of 61.5°F (16.4°C). October brings a decrease in the average high-temperature, shifting from a moderately hot 75.6°F (24.2°C) in September to a comfortable 61.5°F (16.4°C). Weather in October »
Weather in November
November, the last month of the autumn in Rio, is another chilly month, with temperature in the range of an average low of 33.8°F (1°C) and an average high of 47.5°F (8.6°C). As November arrives, Rio's weather displays a decrease in high-temperatures, transitioning from October's refreshing 61.5°F (16.4°C) to a chilly 47.5°F (8.6°C). Weather in November »
Weather in December
The first month of the winter, December, is still a cold month in Rio, Illinois, with temperature in the range of an average low of 24.6°F (-4.1°C) and an average high of 35.4°F (1.9°C). Observing a mild shift, the average high-temperature during December reduces from November's chilly 47.5°F (8.6°C) to an icy 35.4°F (1.9°C). Weather in December »
Updated: Feb 12, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What part of the year is the coldest in Rio?
The coldest period tends to be January, when average temperatures fluctuate between a high of 29.5°F (-1.4°C) and a low of 17.4°F (-8.1°C).
What is the driest month in Rio?
January and December are months with the least rain when the rain falls for 4 days and typically aggregates up to 0.47" (12mm) of rain.
How many days does it rain in Rio?
Throughout the year, in Rio, there are 109.9 rainfall days, and 11.14" (283mm) of precipitation is accumulated.
When does it snow in Rio?
Months with snowfall in Rio are January through April, October through December.
When does it snow the most in Rio?
The month with the most snowfall in Rio is January, when snow falls for 8.8 days and typically aggregates up to 1.38" (35mm) of snow.
How many days does it snow in Rio?
Throughout the year, there are 28 snowfall days, and 4.53" (115mm) of snow is accumulated.
What is the month with the least sunshine in Rio?
The month with the least sunshine is January, with an average of 4h of sunshine.
When is Daylight Saving Time (DST) in Rio?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Rio, Illinois, and the time zone changes from CST to CDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from CDT to CST.
What is the rainiest month in Rio?
May is the month with the most rainfall in Rio. Rain falls for 15.2 days and accumulates 1.65" (42mm) of precipitation.
When it does not snow in Rio?
In Rio, Illinois, snow does not fall in May through September.
When are the longest days in Rio?
With an average of 15h and 6min of daylight, June has the longest days of the year in Rio, Illinois.
What month has the most sunshine in Rio?
The month with the most sunshine in Rio, Illinois, is June, with an average of 10.1h of sunshine.
What are the months with the highest UV index in Rio?
The months with the highest UV index in Rio are June and July, with an average maximum UV index of 6.
What is the warmest month in Rio?
Rio experiences its highest temperatures in July, with an average peak of 81.1°F (27.3°C) and a low of 64.9°F (18.3°C).
What is the most humid month in Rio?
With an average relative humidity of 84%, July is the most humid month.
What is the least humid month in Rio?
October is the least humid month, with an average relative humidity of 72%.
What is the month with the shortest days in Rio?
December has the shortest days of the year in Rio, Illinois, with an average of 9h and 18min of daylight.
What is the month with the lowest UV index in Rio?
With an average maximum UV index of 1, December is the month with the lowest UV index in Rio, Illinois.
Average temperature
Rio, IL
The warmest month (with the highest average high temperature) is July (81.1°F).
The month with the lowest average high temperature is January (29.5°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 (17.4°F).
Average pressure
Rio, IL
- Average pressure in January:
30.14"Hg - Average pressure in February:
30.12"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.93"Hg - Average pressure in May:
29.95"Hg - Average pressure in June:
29.91"Hg
- Average pressure in July:
29.96"Hg - Average pressure in August:
29.97"Hg - Average pressure in September:
30.02"Hg - Average pressure in October:
30.01"Hg - Average pressure in November:
30.1"Hg - Average pressure in December:
30.11"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Rio, IL
- Average wind speed in January:
10.6mph - Average wind speed in February:
10.6mph - Average wind speed in March:
10.6mph - Average wind speed in April:
10.8mph - Average wind speed in May:
9.1mph - Average wind speed in June:
8mph
- Average wind speed in July:
6.8mph - Average wind speed in August:
6.8mph - Average wind speed in September:
7.9mph - Average wind speed in October:
9.5mph - Average wind speed in November:
10.3mph - Average wind speed in December:
9.9mph
The windiest month (with the highest average wind speed) is April (10.8mph).
The calmest months (with the lowest average wind speed) are July and August (6.8mph).
Average humidity
Rio, IL
The month with the highest relative humidity is July (84%).
The month with the lowest relative humidity is October (72%).
Average rainfall
Rio, IL
- Average rainfall in January:
0.47" - Average rainfall in February:
0.59" - Average rainfall in March:
0.75" - Average rainfall in April:
1.3" - Average rainfall in May:
1.65" - Average rainfall in June:
1.34"
- Average rainfall in July:
1.14" - Average rainfall in August:
0.83" - Average rainfall in September:
1.02" - Average rainfall in October:
0.98" - Average rainfall in November:
0.59" - Average rainfall in December:
0.47"
The wettest month (with the highest rainfall) is May (1.65").
The driest months (with the least rainfall) are January and December (0.47").
Average rainfall days
Rio, IL
- Average rainfall days in January:
4 days - Average rainfall days in February:
3.9 days - Average rainfall days in March:
9.3 days - Average rainfall days in April:
11.8 days - Average rainfall days in May:
15.2 days - Average rainfall days in June:
14.5 days
- Average rainfall days in July:
12.8 days - Average rainfall days in August:
10.1 days - Average rainfall days in September:
8.7 days - Average rainfall days in October:
8.8 days - Average rainfall days in November:
6.3 days - Average rainfall days in December:
4.5 days
The month with the highest number of rainy days is May (15.2 days).
The month with the least rainy days is February (3.9 days).
Average snowfall
Rio, IL
The month with the highest snowfall is January (1.38").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Rio, IL
- Average snowfall days in January:
8.8 days - Average snowfall days in February:
6.8 days - Average snowfall days in March:
3.2 days - Average snowfall days in April:
0.9 days - Average snowfall days in May:
0 days - Average snowfall days in June:
0 days
- Average snowfall days in July:
0 days - Average snowfall days in August:
0 days - Average snowfall days in September:
0 days - Average snowfall days in October:
0.3 days - Average snowfall days in November:
2 days - Average snowfall days in December:
6 days
The month with the highest number of snowfall days is January (8.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Rio, IL
- Average daylight in January:
9h and 4min - Average daylight in February:
10h and 4min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 2min - Average daylight in May:
14h and 3min - Average daylight in June:
15h and 1min
- Average daylight in July:
14h and 5min - Average daylight in August:
13h and 5min - Average daylight in September:
12h and 3min - Average daylight in October:
11h and 1min - Average daylight in November:
9h and 5min - Average daylight in December:
9h and 2min
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 January:
4h and 0min - Average sunshine in February:
4h and 1min - Average sunshine in March:
6h and 2min - Average sunshine in April:
7h and 5min - Average sunshine in May:
8h and 4min - Average sunshine in June:
10h and 1min
- Average sunshine in July:
10h and 0min - Average sunshine in August:
9h and 5min - Average sunshine in September:
9h and 1min - Average sunshine in October:
5h and 4min - Average sunshine in November:
5h and 2min - Average sunshine in December:
4h and 2min
The month with the most sunshine is June (Average sunshine: 10h and 6min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days
Rio, IL
- Average sunshine days in January:
20 days - Average sunshine days in February:
18.9 days - Average sunshine days in March:
17.5 days - Average sunshine days in April:
16.3 days - Average sunshine days in May:
13.7 days - Average sunshine days in June:
12.4 days
- Average sunshine days in July:
13.2 days - Average sunshine days in August:
16.8 days - Average sunshine days in September:
18.4 days - Average sunshine days in October:
19.9 days - Average sunshine days in November:
20.5 days - Average sunshine days in December:
21.6 days
The month with the most sunshine days is December (21.6 days).
The month with the least sunshine days is June (12.4 days).
Average UV index
Rio, IL
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is December (UV index 1).
Average cloud cover
Rio, IL
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is September (Cloud cover 30).
Average visibility
Rio, IL
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).
Rio, Illinois, USA
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