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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 Dewey, Illinois, is a freezing cold winter month, with an average temperature ranging between max 31.5°F (-0.3°C) and min 19.8°F (-6.8°C). January brings the lowest temperatures, with an average high of 31.5°F (-0.3°C) and an average low of 19.8°F (-6.8°C). Weather in January »
Weather in February
The last month of the winter, February, is an icy month in Dewey, Illinois, with an average temperature fluctuating between 23.5°F (-4.7°C) and 36.1°F (2.3°C). Dewey, Illinois, marks the start of February with an average high-temperature of a wintry 36.1°F (2.3°C), hinting at a slight fluctuation from January's 31.5°F (-0.3°C). Weather in February »
Weather in March
March, the first month of the spring in Dewey, is a frosty month, with an average temperature varying between 34.5°F (1.4°C) and 49.1°F (9.5°C). Dewey's transition into March is marked by a temperature shift, moving from a cold 36.1°F (2.3°C) in February to a chilly 49.1°F (9.5°C). Weather in March »
Weather in April
April in Dewey, Illinois, is a comfortable spring month, with temperature in the range of an average low of 45.3°F (7.4°C) and an average high of 61.2°F (16.2°C). April's arrival brings a temperature shift, moving from a frosty 49.1°F (9.5°C) in March to a refreshing 61.2°F (16.2°C). Weather in April »
Weather in May
May, the last month of the spring in Dewey, is an agreeable month, with temperature in the range of an average high of 72.1°F (22.3°C) and an average low of 55.6°F (13.1°C). Dewey in May sees a temperature change, with average high-temperatures moving from an enjoyable 61.2°F (16.2°C) in April to a pleasant 72.1°F (22.3°C). Weather in May »
Weather in June
June, the first month of the summer in Dewey, is a moderately hot month, with an average temperature ranging between min 63.7°F (17.6°C) and max 79.9°F (26.6°C). A slight uplift of average high-temperatures is noted in June, with temperatures adjusting from an agreeable 72.1°F (22.3°C) in May to a moderately hot 79.9°F (26.6°C). Weather in June »
Weather in July
July, the same as June, is a moderately hot summer month in Dewey, Illinois, with an average temperature varying between 81°F (27.2°C) and 64.9°F (18.3°C). July is the warmest month, exhibiting average temperatures of 81°F (27.2°C) at the peak and 64.9°F (18.3°C) at the base. During July, the heat index is estimated at a hot 87.8°F (31°C). Weather in July »
Weather in August
August, the last month of the summer in Dewey, is also a moderately hot month, with an average temperature fluctuating between 80.2°F (26.8°C) and 63.1°F (17.3°C). At the onset of August, Dewey records an average high-temperature of a still warm 80.2°F (26.8°C), showing little deviation from the preceding month. Weather in August »
Weather in September
The first month of the autumn, September, is also a moderately hot month in Dewey, Illinois, with temperature in the range of an average low of 57.6°F (14.2°C) and an average high of 75.9°F (24.4°C). Dewey's weather, upon September's arrival, documents an average high-temperature of a still warm 75.9°F (24.4°C), nearly identical to the prior month. Weather in September »
Weather in October
October, the same as September, is another enjoyable autumn month in Dewey, Illinois, with an average temperature ranging between min 47.1°F (8.4°C) and max 63°F (17.2°C). A shift in the average high-temperature occurs in October, reducing from a warm 75.9°F (24.4°C) in September to a refreshing 63°F (17.2°C). Weather in October »
Weather in November
The last month of the autumn, November, is also a frosty month in Dewey, Illinois, with an average temperature fluctuating between 35.6°F (2°C) and 48.6°F (9.2°C). As November arrives, a noticeable drop in the average high-temperature is witnessed, moving from a refreshing 63°F (17.2°C) in October to a frosty 48.6°F (9.2°C). Weather in November »
Weather in December
December, the first month of the winter in Dewey, is also a wintry month, with an average temperature ranging between min 27.3°F (-2.6°C) and max 37.6°F (3.1°C). Welcoming December, Dewey observes a shift in the average high-temperature, falling from November's chilly 48.6°F (9.2°C) to a cold 37.6°F (3.1°C). Weather in December »
Updated: Jun 19, 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 month is the coldest?
During the coldest month in Dewey, January, temperatures average a high of 31.5°F (-0.3°C) and a low of 19.8°F (-6.8°C).
How many days does it rain?
In Dewey, during the entire year, the rain falls for 115.9 days and collects up to 10.87" (276mm) of precipitation.
When does it snow?
January through April, November and December are months with snowfall.
What is the snowiest month?
January is the month with the most snowfall. Snow falls for 8.3 days and accumulates 1.3" (33mm) of snow.
How many days does it snow?
In Dewey, during the entire year, snow falls for 24.9 days and aggregates up to 3.27" (83mm) of snow.
What is the month with the least sunshine?
With an average of 4h of sunshine, January has the least sunshine of the year.
When is the lowest UV index?
The months with the lowest UV index are January, February, November and December, with an average maximum UV index of 2.
What is the driest month?
The month with the least rainfall is February, when the rain falls for 4.8 days and typically collects 0.51" (13mm) of precipitation.
When is Daylight Saving Time (DST)?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts, 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 Dewey?
May is the month with the most rainfall. Rain falls for 14.4 days and accumulates 1.46" (37mm) of precipitation.
When it does not snow?
In Dewey, snow does not fall in May through October.
When are the longest days?
June has the longest days of the year, with an average of 15h and 0min of daylight.
What month has the most sunshine?
With an average of 10.1h of sunshine, June has the most sunshine of the year in Dewey.
What is the month with the highest UV index?
June through August, with an average maximum UV index of 6, are months with the highest UV index.
What time of the year is the hottest?
Dewey's temperature records reveal July as the warmest month, marked by average highs of 81°F (27.2°C) and lows of 64.9°F (18.3°C).
What is the most humid month?
July is the most humid month, with an average relative humidity of 85%.
What is the least humid month?
The least humid month is October, with an average relative humidity of 71%.
What is the month with the shortest days?
The month with the shortest days is December, with an average of 9h and 24min of daylight.
Average temperature
Dewey, IL
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (31.5°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 (19.8°F).
Average pressure
Dewey, IL
- Average pressure in January:
30.14"Hg - Average pressure in February:
30.11"Hg - Average pressure in March:
30.08"Hg - Average pressure in April:
29.94"Hg - Average pressure in May:
29.96"Hg - Average pressure in June:
29.92"Hg
- Average pressure in July:
29.97"Hg - Average pressure in August:
29.98"Hg - Average pressure in September:
30.03"Hg - Average pressure in October:
30.02"Hg - Average pressure in November:
30.12"Hg - Average pressure in December:
30.12"Hg
The month with the highest atmospheric pressure is January (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed
Dewey, IL
- Average wind speed in January:
10.9mph - Average wind speed in February:
10.7mph - Average wind speed in March:
10.4mph - Average wind speed in April:
10.6mph - Average wind speed in May:
9mph - Average wind speed in June:
7.8mph
- Average wind speed in July:
6.5mph - Average wind speed in August:
6.4mph - Average wind speed in September:
7.5mph - Average wind speed in October:
9.6mph - Average wind speed in November:
10.3mph - Average wind speed in December:
10.3mph
The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).
Average humidity
Dewey, IL
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (71%).
Average rainfall
Dewey, IL
- Average rainfall in January:
0.75" - Average rainfall in February:
0.51" - Average rainfall in March:
0.83" - Average rainfall in April:
1.02" - Average rainfall in May:
1.46" - Average rainfall in June:
1.34"
- Average rainfall in July:
1.14" - Average rainfall in August:
0.98" - Average rainfall in September:
0.67" - Average rainfall in October:
0.94" - Average rainfall in November:
0.67" - Average rainfall in December:
0.55"
The wettest month (with the highest rainfall) is May (1.46").
The driest month (with the least rainfall) is February (0.51").
Average rainfall days
Dewey, IL
- Average rainfall days in January:
4.5 days - Average rainfall days in February:
4.8 days - Average rainfall days in March:
9.8 days - Average rainfall days in April:
12.6 days - Average rainfall days in May:
14.4 days - Average rainfall days in June:
13 days
- Average rainfall days in July:
13.3 days - Average rainfall days in August:
11.3 days - Average rainfall days in September:
9.1 days - Average rainfall days in October:
9.5 days - Average rainfall days in November:
7.4 days - Average rainfall days in December:
6.2 days
The month with the highest number of rainy days is May (14.4 days).
The month with the least rainy days is January (4.5 days).
Average snowfall
Dewey, IL
The month with the highest snowfall is January (1.3").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days
Dewey, IL
- Average snowfall days in January:
8.3 days - Average snowfall days in February:
6.7 days - Average snowfall days in March:
2 days - Average snowfall days in April:
0.8 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 days - Average snowfall days in November:
1.6 days - Average snowfall days in December:
5.5 days
The month with the highest number of snowfall days is January (8.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average daylight / Average sunshine
Dewey, 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 2min - Average daylight in June:
15h and 0min
- Average daylight in July:
14h and 4min - Average daylight in August:
13h and 4min - Average daylight in September:
12h and 2min - Average daylight in October:
11h and 1min - Average daylight in November:
10h and 0min - Average daylight in December:
9h and 2min
The month with the longest days is June (Average daylight: 15h and 0min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- 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:
8h and 1min - Average sunshine in May:
9h and 1min - Average sunshine in June:
10h and 1min
- Average sunshine in July:
9h and 5min - Average sunshine in August:
10h and 0min - Average sunshine in September:
8h and 5min - Average sunshine in October:
6h and 1min - Average sunshine in November:
5h and 2min - Average sunshine in December:
4h and 3min
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
Dewey, IL
- Average sunshine days in January:
21.3 days - Average sunshine days in February:
18.9 days - Average sunshine days in March:
18.2 days - Average sunshine days in April:
15.4 days - Average sunshine days in May:
14.1 days - Average sunshine days in June:
13.3 days
- Average sunshine days in July:
12.3 days - Average sunshine days in August:
16.2 days - Average sunshine days in September:
17.5 days - Average sunshine days in October:
20 days - Average sunshine days in November:
21.4 days - Average sunshine days in December:
20.5 days
The month with the most sunshine days is November (21.4 days).
The month with the least sunshine days is July (12.3 days).
Average UV index
Dewey, IL
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
Dewey, IL
The month with the most cloud cover is January (Cloud cover 58).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility
Dewey, IL
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).
Dewey, Illinois, USA
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