Climate and monthly weather forecastSullivan, WI
Climate and monthly weather forecast
Weather in January
January, the same as December, in Sullivan, Wisconsin, is another subzero cold winter month, with an average temperature varying between 12.2°F (-11°C) and 24.3°F (-4.3°C). January is the month when Sullivan sees the lowest average temperatures, with a high of 24.3°F (-4.3°C) and a low of 12.2°F (-11°C). Weather in January »Weather in February
February, the last month of the winter in Sullivan, is also a subzero cold month, with an average temperature varying between 15.3°F (-9.3°C) and 28°F (-2.2°C). Welcoming February, Sullivan notes an average high-temperature of a still subzero cold 28°F (-2.2°C), nearly consistent with January's 24.3°F (-4.3°C). Weather in February »Weather in March
The first month of the spring, March, is an icy month in Sullivan, Wisconsin, with an average temperature fluctuating between 42.1°F (5.6°C) and 27.1°F (-2.7°C). March comes with an increase, with the average high-temperature moving from a freezing cold 28°F (-2.2°C) in February to a wintry 42.1°F (5.6°C). Weather in March »Weather in April
April is a fresh spring month in Sullivan, Wisconsin, with an average temperature ranging between max 53.8°F (12.1°C) and min 37.2°F (2.9°C). April brings a rise in the average high-temperature, transitioning from March's icy 42.1°F (5.6°C) to a cool 53.8°F (12.1°C). Weather in April »Weather in May
The last month of the spring, May, is an enjoyable month in Sullivan, Wisconsin, with temperature in the range of an average high of 66°F (18.9°C) and an average low of 48.4°F (9.1°C). As April gives way to May, the average high-temperature displays an increase, moving from a fresh 53.8°F (12.1°C) to a refreshing 66°F (18.9°C). Weather in May »Weather in June
June, the first month of the summer in Sullivan, is a moderately hot month, with an average temperature varying between 57.4°F (14.1°C) and 74.8°F (23.8°C). June's onset witnesses a minor shift in the average high-temperature, moving from a refreshing 66°F (18.9°C) in May to a moderately hot 74.8°F (23.8°C). Weather in June »Weather in July
July, the same as June, is another warm summer month in Sullivan, Wisconsin, with an average temperature varying between 79.3°F (26.3°C) and 61.5°F (16.4°C). The month of July, characterized by an average high of 79.3°F (26.3°C) and a low of 61.5°F (16.4°C), is recognized as the warmest. Weather in July »Weather in August
August, the last month of the summer in Sullivan, is another warm month, with an average temperature fluctuating between 59.9°F (15.5°C) and 77.5°F (25.3°C). The commencement of August introduces an average high-temperature of a still moderately hot 77.5°F (25.3°C), closely mirroring the preceding month. Weather in August »Weather in September
September, the first month of the autumn in Sullivan, is also an agreeable month, with an average temperature ranging between max 71.8°F (22.1°C) and min 52.7°F (11.5°C). Sullivan experiences a moderate temperature shift at the start of September, with average high-temperatures adjusting a bit from a moderately hot 77.5°F (25.3°C) in August to an agreeable 71.8°F (22.1°C). Weather in September »Weather in October
October, the same as September, in Sullivan, Wisconsin, is another refreshing autumn month, with an average temperature varying between 42.1°F (5.6°C) and 58.1°F (14.5°C). Sullivan's weather changes with the onset of October, slightly falling from an agreeable 71.8°F (22.1°C) in September to a mild 58.1°F (14.5°C). Weather in October »Weather in November
The last month of the autumn, November, is also a frosty month in Sullivan, Wisconsin, with an average temperature ranging between min 30.4°F (-0.9°C) and max 43.7°F (6.5°C). As Sullivan transitions into November, a noticeable drop in the average high-temperature is observed, falling from a moderate 58.1°F (14.5°C) in October to a frosty 43.7°F (6.5°C). Weather in November »Weather in December
December, the first month of the winter in Sullivan, is also a subzero cold month, with an average temperature ranging between max 31.1°F (-0.5°C) and min 21.2°F (-6°C). December shows a mild decline in the average high-temperature, falling from November's chilly 43.7°F (6.5°C) to a subzero cold 31.1°F (-0.5°C). Weather in December »Updated: Feb 14, 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
With an average high-temperature of 24.3°F (-4.3°C) and an average low-temperature of 12.2°F (-11°C), January is the coldest month in Sullivan.
The most humid month in Sullivan, Wisconsin, is January, with an average relative humidity of 88%.
Throughout the year, in Sullivan, there are 121.6 rainfall days, and 14.06" (357mm) of precipitation is accumulated.
January through May, October through December are months with snowfall in Sullivan, Wisconsin.
January is the month with the most snowfall in Sullivan. Snow falls for 12.8 days and accumulates 2.13" (54mm) of snow.
Throughout the year, there are 46.4 snowfall days, and 7.48" (190mm) of snow is accumulated.
The month with the least sunshine in Sullivan is January, with an average of 3.4h of sunshine.
The months with the lowest UV index in Sullivan, Wisconsin, are January, November and December, with an average maximum UV index of 1.
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.
The least humid month is April, with an average relative humidity of 76%.
The months with the highest UV index are May through August, with an average maximum UV index of 5.
In Sullivan, snow does not fall in June through September.
June has the longest days of the year in Sullivan, with an average of 15h and 18min of daylight.
Sullivan's warmest month, July, registers temperatures that range from a high of 79.3°F (26.3°C) to a low of 61.5°F (16.4°C).
The month with the most rainfall in Sullivan is July, when the rain falls for 15.7 days and typically aggregates up to 1.93" (49mm) of precipitation.
The months with the most sunshine in Sullivan, Wisconsin, are July and August, with an average of 9.7h of sunshine.
December is the month with the least rainfall. Rain falls for 6.5 days and accumulates 0.55" (14mm) of precipitation.
The month with the shortest days in Sullivan is December, with an average of 9h and 6min of daylight.
Average temperature
Sullivan, WI
The warmest month (with the highest average high temperature) is July (79.3°F).
The month with the lowest average high temperature is January (24.3°F).
The month with the highest average low temperature is July (61.5°F).
The coldest month (with the lowest average low temperature) is January (12.2°F).
Average pressure
Sullivan, WI
- Average pressure in January:
30.1"Hg - Average pressure in February:
30.1"Hg - Average pressure in March:
30.09"Hg - Average pressure in April:
29.96"Hg - Average pressure in May:
29.96"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:
30.03"Hg - Average pressure in October:
29.99"Hg - Average pressure in November:
30.08"Hg - Average pressure in December:
30.09"Hg
The months with the highest atmospheric pressure are January and February (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.91"Hg).
Average wind speed
Sullivan, WI
- Average wind speed in January:
9.6mph - Average wind speed in February:
9.7mph - Average wind speed in March:
9.4mph - Average wind speed in April:
9.9mph - Average wind speed in May:
8.5mph - Average wind speed in June:
7.4mph
- Average wind speed in July:
6.5mph - Average wind speed in August:
6.3mph - Average wind speed in September:
7.2mph - Average wind speed in October:
8.6mph - Average wind speed in November:
9.2mph - Average wind speed in December:
9.1mph
The windiest month (with the highest average wind speed) is April (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.3mph).
Average humidity
Sullivan, WI
The month with the highest relative humidity is January (88%).
The month with the lowest relative humidity is April (76%).
Average rainfall
Sullivan, WI
- Average rainfall in January:
0.63" - Average rainfall in February:
0.59" - Average rainfall in March:
0.71" - Average rainfall in April:
1.57" - Average rainfall in May:
1.57" - Average rainfall in June:
1.65"
- Average rainfall in July:
1.93" - Average rainfall in August:
1.69" - Average rainfall in September:
1.02" - Average rainfall in October:
1.34" - Average rainfall in November:
0.79" - Average rainfall in December:
0.55"
The wettest month (with the highest rainfall) is July (1.93").
The driest month (with the least rainfall) is December (0.55").
Average rainfall days
Sullivan, WI
- Average rainfall days in January:
2.8 days - Average rainfall days in February:
3.6 days - Average rainfall days in March:
8.4 days - Average rainfall days in April:
12.4 days - Average rainfall days in May:
15.7 days - Average rainfall days in June:
13.8 days
- Average rainfall days in July:
15.7 days - Average rainfall days in August:
13.8 days - Average rainfall days in September:
10.5 days - Average rainfall days in October:
11.4 days - Average rainfall days in November:
7 days - Average rainfall days in December:
6.5 days
The months with the highest number of rainy days are May and July (15.7 days).
The month with the least rainy days is January (2.8 days).
Average snowfall
Sullivan, WI
- Average snowfall in January:
2.13" - Average snowfall in February:
1.5" - Average snowfall in March:
0.67" - Average snowfall in April:
0.47" - Average snowfall in May:
0.04" - Average snowfall in June:
0"
The month with the highest snowfall is January (2.13").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days
Sullivan, WI
- Average snowfall days in January:
12.8 days - Average snowfall days in February:
10.6 days - Average snowfall days in March:
6.2 days - Average snowfall days in April:
2.3 days - Average snowfall days in May:
0.3 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:
0.7 days - Average snowfall days in November:
4 days - Average snowfall days in December:
9.5 days
The month with the highest number of snowfall days is January (12.8 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight / Average sunshine
Sullivan, WI
- Average daylight in January:
9h and 24min - Average daylight in February:
10h and 36min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 24min - Average daylight in May:
14h and 42min - Average daylight in June:
15h and 18min
- Average daylight in July:
15h and 0min - Average daylight in August:
13h and 54min - Average daylight in September:
12h and 30min - Average daylight in October:
11h and 0min - Average daylight in November:
9h and 42min - Average daylight in December:
9h and 6min
The month with the longest days is June (Average daylight: 15h and 18min).
The month with the shortest days is December (Average daylight: 9h and 6min).
- Average sunshine in January:
3h and 24min - Average sunshine in February:
3h and 36min - Average sunshine in March:
5h and 48min - Average sunshine in April:
7h and 18min - Average sunshine in May:
8h and 30min - Average sunshine in June:
9h and 24min
- Average sunshine in July:
9h and 42min - Average sunshine in August:
9h and 42min - Average sunshine in September:
8h and 30min - Average sunshine in October:
5h and 18min - Average sunshine in November:
4h and 54min - Average sunshine in December:
3h and 48min
The months with the most sunshine are July and August (Average sunshine: 9h and 42min).
The month with the least sunshine is January (Average sunshine: 3h and 24min).
Average sunshine days
Sullivan, WI
- Average sunshine days in January:
16.8 days - Average sunshine days in February:
15.8 days - Average sunshine days in March:
17.3 days - Average sunshine days in April:
14.8 days - Average sunshine days in May:
13.1 days - Average sunshine days in June:
12.4 days
- Average sunshine days in July:
11.6 days - Average sunshine days in August:
13 days - Average sunshine days in September:
16.8 days - Average sunshine days in October:
17.2 days - Average sunshine days in November:
18.7 days - Average sunshine days in December:
17.7 days
The month with the most sunshine days is November (18.7 days).
The month with the least sunshine days is July (11.6 days).
Average UV index
Sullivan, WI
The months with the highest UV index are May, June, July and August (UV index 5).
The months with the lowest UV index are January, November and December (UV index 1).
Average cloud cover
Sullivan, WI
The month with the most cloud cover is January (Cloud cover 65).
The month with the least cloud cover is August (Cloud cover 34).
Average visibility
Sullivan, WI
The months with the highest visibility are March, April, May, June, October, November and December (6mi).
The months with the lowest visibility are January, February, July, August and September (5mi).
