Climate and monthly weather forecastSeymour, IL
Climate and monthly weather forecast
Weather in January
January, like December, is a freezing cold winter month in Seymour, Illinois, with an average temperature fluctuating between 31.5°F (-0.3°C) and 19.9°F (-6.7°C). Seymour reaches its lowest average temperatures in January, measuring 31.5°F (-0.3°C) at the peak and 19.9°F (-6.7°C) at the lowest. Weather in January »Weather in February
February, the last month of the winter in Seymour, is a cold month, with an average temperature ranging between max 36.9°F (2.7°C) and min 23.7°F (-4.6°C). The shift into February is marked by a modest rise in the average high-temperature, moving from January's subzero cold 31.5°F (-0.3°C) to a wintry 36.9°F (2.7°C). Weather in February »Weather in March
The first month of the spring, March, is a frosty month in Seymour, Illinois, with an average temperature ranging between max 49.3°F (9.6°C) and min 34.5°F (1.4°C). March's arrival signals an increase in average high-temperatures, moving from February's cold 36.9°F (2.7°C) to a chilly 49.3°F (9.6°C). Weather in March »Weather in April
April is a comfortable spring month in Seymour, Illinois, with an average temperature fluctuating between 45.5°F (7.5°C) and 61.3°F (16.3°C). Noticing a change, the average high-temperature during April moves from March's frosty 49.3°F (9.6°C) to a comfortable 61.3°F (16.3°C). Weather in April »Weather in May
May, the last month of the spring in Seymour, is an agreeable month, with temperature in the range of an average low of 55.9°F (13.3°C) and an average high of 72.3°F (22.4°C). As Seymour enters May, the average high-temperature increases from the an enjoyable 61.3°F (16.3°C) of April to an agreeable 72.3°F (22.4°C). Weather in May »Weather in June
June, the first month of the summer in Seymour, is a warm month, with temperature in the range of an average low of 63.9°F (17.7°C) and an average high of 79.9°F (26.6°C). Seymour perceives a slight temperature ascent during June, with average high-temperatures adjusting from a pleasant 72.3°F (22.4°C) in May to a moderately hot 79.9°F (26.6°C). Weather in June »Weather in July
July, like June, in Seymour, Illinois, is another warm summer month, with an average temperature varying between 64.9°F (18.3°C) and 81.1°F (27.3°C). July, with its average high-temperature of 81.1°F (27.3°C) and an average low-temperature of 64.9°F (18.3°C), holds the record as the warmest month. For July, the heat index is computed to be 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 Seymour, Illinois, with an average temperature varying between 63.1°F (17.3°C) and 80.2°F (26.8°C). Seymour experiences an average high-temperature of a still moderately hot 80.2°F (26.8°C) in August, marking an insignificant shift from 81.1°F (27.3°C) in July. Weather in August »Weather in September
The first month of the autumn, September, is also a moderately hot month in Seymour, Illinois, with an average temperature ranging between min 58.3°F (14.6°C) and max 76.1°F (24.5°C). In September, Seymour experiences a barely noticeable shift in meteorological conditions, with average high-temperatures moving from 80.2°F (26.8°C) in August to a still warm 76.1°F (24.5°C). Weather in September »Weather in October
October, like September, in Seymour, Illinois, is another comfortable autumn month, with an average temperature varying between 47.3°F (8.5°C) and 63.5°F (17.5°C). October implies a gentle temperature shift, with average high-temperatures reducing from September's warm 76.1°F (24.5°C) to an enjoyable 63.5°F (17.5°C). Weather in October »Weather in November
November, the last month of the autumn in Seymour, is also a frosty month, with an average temperature varying between 35.6°F (2°C) and 49.1°F (9.5°C). The beginning of November signals a clear reduction in the average high-temperature, falling from an enjoyable 63.5°F (17.5°C) in October to a chilly 49.1°F (9.5°C). Weather in November »Weather in December
December, the first month of the winter in Seymour, is also an icy month, with an average temperature fluctuating between 27.5°F (-2.5°C) and 37.6°F (3.1°C). Transition from November to December is accompanied by a temperature drop, with average high-temperatures decreasing from a frosty 49.1°F (9.5°C) to an icy 37.6°F (3.1°C). Weather in December »Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature
Seymour, 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 (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 (19.9°F).
Average pressure
Seymour, 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
Seymour, IL
- Average wind speed in January:
10.9mph - Average wind speed in February:
10.8mph - Average wind speed in March:
10.4mph - Average wind speed in April:
10.7mph - 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:
7.4mph - 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
Seymour, IL
The month with the highest relative humidity is July (85%).
The month with the lowest relative humidity is October (70%).
Average rainfall
Seymour, IL
- Average rainfall in January:
2.01" - Average rainfall in February:
1.81" - Average rainfall in March:
2.72" - Average rainfall in April:
3.31" - Average rainfall in May:
3.9" - Average rainfall in June:
3.27"
- Average rainfall in July:
2.44" - Average rainfall in August:
2.2" - Average rainfall in September:
1.77" - Average rainfall in October:
2.64" - Average rainfall in November:
2.01" - Average rainfall in December:
1.65"
The wettest month (with the highest rainfall) is May (3.9").
The driest month (with the least rainfall) is December (1.65").
Average rainfall days
Seymour, IL
- Average rainfall days in January:
6.7 days - Average rainfall days in February:
6.3 days - Average rainfall days in March:
13.4 days - Average rainfall days in April:
15.9 days - Average rainfall days in May:
18.8 days - Average rainfall days in June:
16.6 days
- Average rainfall days in July:
17.8 days - Average rainfall days in August:
14.1 days - Average rainfall days in September:
12.8 days - Average rainfall days in October:
12.3 days - Average rainfall days in November:
9.8 days - Average rainfall days in December:
8.4 days
The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is February (6.3 days).
Average snowfall
Seymour, IL
The month with the highest snowfall is January (4.25").
The months with the least snowfall are May, June, July, August and September (0").
Average snowfall days
Seymour, IL
- Average snowfall days in January:
11.4 days - Average snowfall days in February:
8.6 days - Average snowfall days in March:
3.3 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:
0.2 days - Average snowfall days in November:
2.4 days - Average snowfall days in December:
7.1 days
The month with the highest number of snowfall days is January (11.4 days).
The months with the least snowfall days are May, June, July, August and September (0 days).
Average daylight / Average sunshine
Seymour, IL
- Average daylight in January:
9h and 42min - Average daylight in February:
10h and 42min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 18min - Average daylight in May:
14h and 24min - Average daylight in June:
15h and 0min
- Average daylight in July:
14h and 42min - Average daylight in August:
13h and 42min - Average daylight in September:
12h and 24min - Average daylight in October:
11h and 6min - Average daylight in November:
10h and 0min - Average daylight in December:
9h and 24min
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 12min - Average sunshine in March:
6h and 18min - Average sunshine in April:
8h and 6min - Average sunshine in May:
9h and 6min - Average sunshine in June:
10h and 12min
- Average sunshine in July:
9h and 54min - Average sunshine in August:
9h and 54min - Average sunshine in September:
8h and 54min - Average sunshine in October:
6h and 6min - Average sunshine in November:
5h and 24min - Average sunshine in December:
4h and 30min
The month with the most sunshine is June (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 4h and 0min).
Average sunshine days
Seymour, IL
- Average sunshine days in January:
14.6 days - Average sunshine days in February:
13.8 days - Average sunshine days in March:
14 days - Average sunshine days in April:
11.6 days - Average sunshine days in May:
10.3 days - Average sunshine days in June:
10.2 days
- Average sunshine days in July:
10.5 days - Average sunshine days in August:
14.8 days - Average sunshine days in September:
15.3 days - Average sunshine days in October:
16.5 days - Average sunshine days in November:
18 days - Average sunshine days in December:
16.2 days
The month with the most sunshine days is November (18 days).
The month with the least sunshine days is June (10.2 days).
Average UV index
Seymour, 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
Seymour, IL
The month with the most cloud cover is January (Cloud cover 57).
The months with the least cloud cover are August and September (Cloud cover 31).
Average visibility
Seymour, 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).





