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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, like December, is a freezing cold winter month in Seneca, Illinois, with an average temperature fluctuating between 17.2°F (-8.2°C) and 29.1°F (-1.6°C). January is the coldest month, exhibiting average temperatures of 29.1°F (-1.6°C) at the peak and 17.2°F (-8.2°C) at the base. Weather in January »
Weather in February
The last month of the winter, February, is an icy month in Seneca, Illinois, with an average temperature ranging between max 33.4°F (0.8°C) and min 20.7°F (-6.3°C). With the start of February, Seneca measures an average high-temperature of an icy 33.4°F (0.8°C), not significantly differing from January's 29.1°F (-1.6°C). Weather in February »
Weather in March
March, the first month of the spring in Seneca, is a chilly month, with temperature in the range of an average high of 46.9°F (8.3°C) and an average low of 32.5°F (0.3°C). The shift into March is marked by a rise in the average high-temperature, moving from February's wintry 33.4°F (0.8°C) to a frosty 46.9°F (8.3°C). Weather in March »
Weather in April
April in Seneca, Illinois, is a refreshing spring month, with an average temperature ranging between min 42.4°F (5.8°C) and max 58.8°F (14.9°C). As Seneca transitions into April, the average high-temperature is observed to rise from a chilly 46.9°F (8.3°C) in March to a moderate 58.8°F (14.9°C). Weather in April »
Weather in May
May, the last month of the spring in Seneca, is a pleasant month, with temperature in the range of an average high of 70.7°F (21.5°C) and an average low of 53.8°F (12.1°C). The start of May brings a rise in the average high-temperature, moving from a moderate 58.8°F (14.9°C) in April to an agreeable 70.7°F (21.5°C). Weather in May »
Weather in June
The first month of the summer, June, is a moderately hot month in Seneca, Illinois, with an average temperature ranging between min 61.5°F (16.4°C) and max 78.8°F (26°C). As Seneca welcomes June, the average high-temperature displays a subtle shift, adjusting from an agreeable 70.7°F (21.5°C) in May to a moderately hot 78.8°F (26°C). Weather in June »
Weather in July
July, the same as June, is another warm summer month in Seneca, Illinois, with an average temperature ranging between max 81°F (27.2°C) and min 64.2°F (17.9°C). The month of July sees the highest average temperatures, reaching 81°F (27.2°C) at the peak and 64.2°F (17.9°C) at the low. July's average 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 Seneca, is another warm month, with an average temperature varying between 79.5°F (26.4°C) and 62.1°F (16.7°C). August's presence records an average high-temperature of a still warm 79.5°F (26.4°C), closely mirroring July's climate. Weather in August »
Weather in September
The first month of the autumn, September, is also a moderately hot month in Seneca, Illinois, with an average temperature fluctuating between 56.3°F (13.5°C) and 74.7°F (23.7°C). The arrival of September brings an average high-temperature of a still moderately hot 74.7°F (23.7°C), nearly identical to August's 79.5°F (26.4°C). Weather in September »
Weather in October
October, the same as September, is another refreshing autumn month in Seneca, Illinois, with an average temperature varying between 61.7°F (16.5°C) and 45.9°F (7.7°C). In October, the average high-temperature decreases from a moderately hot 74.7°F (23.7°C) in September to a comfortable 61.7°F (16.5°C). Weather in October »
Weather in November
The last month of the autumn, November, is another chilly month in Seneca, Illinois, with an average temperature ranging between min 33.8°F (1°C) and max 47.1°F (8.4°C). In November, the meteorological conditions markedly change with the average high-temperature descending from a comfortable 61.7°F (16.5°C) in October to a frosty 47.1°F (8.4°C). Weather in November »
Weather in December
December, the first month of the winter in Seneca, is still a cold month, with an average temperature varying between 35.1°F (1.7°C) and 25.2°F (-3.8°C). Welcoming December, Seneca observes a shift in the average high-temperature, falling from November's chilly 47.1°F (8.4°C) to an icy 35.1°F (1.7°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 is the coldest time of year in Seneca?
During the coldest month in Seneca, January, temperatures average a high of 29.1°F (-1.6°C) and a low of 17.2°F (-8.2°C).
How much does it rain in Seneca?
In Seneca, Illinois, during the entire year, the rain falls for 154.1 days and collects up to 31.73" (806mm) of precipitation.
When does it snow in Seneca?
Months with snowfall are January through April, October through December.
How much does it snow in Seneca?
Throughout the year, there are 39.8 snowfall days, and 15.71" (399mm) of snow is accumulated.
What is the month with the least sunshine in Seneca?
The month with the least sunshine is January, with an average of 3.9h of sunshine.
What is the month with the lowest UV index in Seneca?
With an average maximum UV index of 1, January is the month with the lowest UV index in Seneca, Illinois.
When does it snow the most in Seneca?
The month with the most snowfall is February, when snow falls for 9.7 days and typically aggregates up to 4.57" (116mm) of snow.
When is Daylight Saving Time (DST) in Seneca?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Seneca, 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 Seneca?
The month with the most rainfall is May, when the rain falls for 18.3 days and typically aggregates up to 4.49" (114mm) of precipitation.
When it does not snow in Seneca?
May through September are months without snowfall.
When are the longest days in Seneca?
The month with the longest days in Seneca, Illinois, is June, with an average of 15h and 6min of daylight.
What are the months with the most sunshine in Seneca?
June and August, with an average of 9.8h of sunshine, are months with the most sunshine in Seneca.
What is the month with the highest UV index in Seneca?
The months with the highest UV index in Seneca are June and July, with an average maximum UV index of 6.
What is the warmest month in Seneca?
In Seneca, Illinois, temperatures reach their average annual highs in July, measuring 81°F (27.2°C) and a minimum average of 64.2°F (17.9°C).
What is the most humid month in Seneca?
The most humid month in Seneca is July, with an average relative humidity of 85%.
What is the least humid month in Seneca?
The least humid month in Seneca, Illinois, is October, with an average relative humidity of 72%.
What is the driest month in Seneca?
The month with the least rainfall in Seneca is December, when the rain falls for 7.6 days and typically collects 1.65" (42mm) of precipitation.
What is the month with the shortest days in Seneca?
The month with the shortest days in Seneca, Illinois, is December, with an average of 9h and 18min of daylight.
Average temperature
Seneca, IL
The warmest month (with the highest average high temperature) is July (81°F).
The month with the lowest average high temperature is January (29.1°F).
The month with the highest average low temperature is July (64.2°F).
The coldest month (with the lowest average low temperature) is January (17.2°F).
Average pressure
Seneca, IL
- Average pressure in January:
30.12"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:
30.01"Hg - Average pressure in November:
30.1"Hg - Average pressure in December:
30.1"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).
Average wind speed
Seneca, IL
- Average wind speed in January:
10.1mph - Average wind speed in February:
10mph - Average wind speed in March:
9.8mph - Average wind speed in April:
10.1mph - Average wind speed in May:
8.6mph - Average wind speed in June:
7.5mph
- Average wind speed in July:
6.3mph - Average wind speed in August:
6.1mph - Average wind speed in September:
7.3mph - Average wind speed in October:
9mph - Average wind speed in November:
9.7mph - Average wind speed in December:
9.5mph
The windiest months (with the highest average wind speed) are January and April (10.1mph).
The calmest month (with the lowest average wind speed) is August (6.1mph).
Average humidity
Seneca, IL
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (72%).
Average rainfall
Seneca, IL
- Average rainfall in January:
1.81" - Average rainfall in February:
1.69" - Average rainfall in March:
2.13" - Average rainfall in April:
3.86" - Average rainfall in May:
4.49" - Average rainfall in June:
3.62"
- Average rainfall in July:
3.27" - Average rainfall in August:
2.28" - Average rainfall in September:
2.32" - Average rainfall in October:
2.87" - Average rainfall in November:
1.73" - Average rainfall in December:
1.65"
The wettest month (with the highest rainfall) is May (4.49").
The driest month (with the least rainfall) is December (1.65").
Average rainfall days
Seneca, IL
- Average rainfall days in January:
6.3 days - Average rainfall days in February:
5.8 days - Average rainfall days in March:
13.2 days - Average rainfall days in April:
17.7 days - Average rainfall days in May:
18.3 days - Average rainfall days in June:
17.3 days
- Average rainfall days in July:
17.6 days - Average rainfall days in August:
15 days - Average rainfall days in September:
12.3 days - Average rainfall days in October:
12.8 days - Average rainfall days in November:
10.2 days - Average rainfall days in December:
7.6 days
The month with the highest number of rainy days is May (18.3 days).
The month with the least rainy days is February (5.8 days).
Average snowfall
Seneca, IL
The month with the highest snowfall is February (4.57").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Seneca, IL
- Average snowfall days in January:
11.9 days - Average snowfall days in February:
9.7 days - Average snowfall days in March:
5.4 days - Average snowfall days in April:
1.4 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:
0.4 days - Average snowfall days in November:
2.8 days - Average snowfall days in December:
8.2 days
The month with the highest number of snowfall days is January (11.9 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Seneca, 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:
3h and 5min - Average sunshine in February:
4h and 0min - Average sunshine in March:
6h and 2min - Average sunshine in April:
7h and 5min - Average sunshine in May:
8h and 5min - Average sunshine in June:
9h and 5min
- Average sunshine in July:
9h and 4min - Average sunshine in August:
9h and 5min - Average sunshine in September:
8h and 5min - Average sunshine in October:
5h and 5min - Average sunshine in November:
5h and 1min - Average sunshine in December:
4h and 2min
The months with the most sunshine are June and August (Average sunshine: 9h and 48min).
The month with the least sunshine is January (Average sunshine: 3h and 54min).
Average sunshine days
Seneca, IL
- Average sunshine days in January:
14 days - Average sunshine days in February:
12.9 days - Average sunshine days in March:
13.2 days - Average sunshine days in April:
10.6 days - Average sunshine days in May:
10.7 days - Average sunshine days in June:
10.1 days
- Average sunshine days in July:
10.8 days - Average sunshine days in August:
13.3 days - Average sunshine days in September:
15.1 days - Average sunshine days in October:
16 days - Average sunshine days in November:
17.1 days - Average sunshine days in December:
16.5 days
The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is June (10.1 days).
Average UV index
Seneca, IL
The months with the highest UV index are June and July (UV index 6).
The month with the lowest UV index is January (UV index 1).
Average cloud cover
Seneca, IL
The month with the most cloud cover is January (Cloud cover 59).
The month with the least cloud cover is September (Cloud cover 32).
Average visibility
Seneca, IL
The months with the highest visibility are February, March, April, May, June, September, October, November and December (6mi).
The months with the lowest visibility are January, July and August (5mi).
Seneca, Illinois, USA
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