Climate and monthly weather forecast
Ontario, WI

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Weather in January

January, like December, is a freezing cold winter month in Ontario, Wisconsin, with an average temperature ranging between min 9.3°F (-12.6°C) and max 22.1°F (-5.5°C). The coldest period tends to be January, when average temperatures fluctuate between a high of 22.1°F (-5.5°C) and a low of 9.3°F (-12.6°C). Weather in January »

Weather in February

February, the last month of the winter in Ontario, is also a subzero cold month, with an average temperature ranging between max 26.1°F (-3.3°C) and min 13.1°F (-10.5°C). The onset of February marks an average high-temperature of a still subzero cold 26.1°F (-3.3°C), hardly differing from January's 22.1°F (-5.5°C). Weather in February »

Weather in March

March, the first month of the spring in Ontario, is an icy month, with an average temperature fluctuating between 25.9°F (-3.4°C) and 40.5°F (4.7°C). Ontario, Wisconsin, experiences a noticeable temperature shift with the start of March, with average high-temperatures moving from a freezing cold 26.1°F (-3.3°C) in February to a wintry 40.5°F (4.7°C). Weather in March »

Weather in April

April is a cool spring month in Ontario, Wisconsin, with an average temperature varying between 53.1°F (11.7°C) and 36°F (2.2°C). The onset of April marks an increase in the average high-temperature, moving from a cold 40.5°F (4.7°C) in March to a fresh 53.1°F (11.7°C). Weather in April »

Weather in May

The last month of the spring, May, is an enjoyable month in Ontario, Wisconsin, with an average temperature fluctuating between 47.5°F (8.6°C) and 65.8°F (18.8°C). Ontario in May sees a temperature change, with average high-temperatures moving from a fresh 53.1°F (11.7°C) in April to a comfortable 65.8°F (18.8°C). Weather in May »

Weather in June

The first month of the summer, June, is a warm month in Ontario, Wisconsin, with an average temperature varying between 75.6°F (24.2°C) and 56.5°F (13.6°C). The average high-temperature increases in June, moving from a comfortable 65.8°F (18.8°C) in May to a warm 75.6°F (24.2°C). Weather in June »

Weather in July

July, the same as June, is a moderately hot summer month in Ontario, Wisconsin, with an average temperature varying between 60.8°F (16°C) and 79.9°F (26.6°C). In Ontario, the highest average temperatures are observed in July, with a high of 79.9°F (26.6°C) and a low of 60.8°F (16°C). Weather in July »

Weather in August

August, the last month of the summer in Ontario, is another warm month, with an average temperature ranging between max 78.4°F (25.8°C) and min 58.5°F (14.7°C). Ontario ushers in August with an average high-temperature of a still warm 78.4°F (25.8°C), showing a close resemblance to the previous month. Weather in August »

Weather in September

The first month of the autumn, September, is also an agreeable month in Ontario, Wisconsin, with temperature in the range of an average high of 71.1°F (21.7°C) and an average low of 51.1°F (10.6°C). September brings a slight decrease in temperature, down from a warm 78.4°F (25.8°C) in August to an agreeable 71.1°F (21.7°C). Weather in September »

Weather in October

October, the same as September, in Ontario, Wisconsin, is another refreshing autumn month, with an average temperature fluctuating between 40.1°F (4.5°C) and 55.9°F (13.3°C). Ontario's October weather is characterized by a distinct downswing in high-temperatures, falling from September's agreeable 71.1°F (21.7°C) to a moderate 55.9°F (13.3°C). Weather in October »

Weather in November

The last month of the autumn, November, is another cold month in Ontario, Wisconsin, with an average temperature ranging between min 28.6°F (-1.9°C) and max 41.5°F (5.3°C). As October gives way to November, the average high-temperature displays a considerable decrease, falling from a mild 55.9°F (13.3°C) to an icy 41.5°F (5.3°C). Weather in November »

Weather in December

The first month of the winter, December, is also a subzero cold month in Ontario, Wisconsin, with an average temperature fluctuating between 28°F (-2.2°C) and 17.6°F (-8°C). During Ontario's transition into December, the average high-temperature lessens, moving from a wintry 41.5°F (5.3°C) in November to a subzero cold 28°F (-2.2°C). Weather in December »
Updated: Jul 15, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the coldest time of year?

January brings the lowest temperatures, with an average high of 22.1°F (-5.5°C) and an average low of 9.3°F (-12.6°C).

What is the most humid month?

January is the most humid month, with an average relative humidity of 90%.

What is the driest month?

The month with the least rainfall is January, when the rain falls for 3.5 days and typically collects 1.1" (28mm) of precipitation.

How many days does it rain?

Throughout the year, there are 131.7 rainfall days, and 27.83" (707mm) of precipitation is accumulated.

When does it snow?

January through May, October through December are months with snowfall.

How many days does it snow?

In Ontario, during the entire year, snow falls for 50.2 days and aggregates up to 21.69" (551mm) of snow.

What is the month with the least sunshine?

The month with the least sunshine is January, with an average of 3h of sunshine.

When is the lowest UV index?

January, February, November and December, with an average maximum UV index of 1, are months with the lowest UV index.

What is the snowiest month?

February is the month with the most snowfall. Snow falls for 10.5 days and accumulates 5.87" (149mm) of snow.

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 least humid month?

The least humid month is April, with an average relative humidity of 77%.

What is the rainiest month?

June is the month with the most rainfall. Rain falls for 16.9 days and accumulates 4.17" (106mm) of precipitation.

When it does not snow?

June through September are months without snowfall.

When are the longest days?

The month with the longest days is June, with an average of 15h and 24min of daylight.

What time of the year is the hottest?

Ontario's warmest month, July, registers temperatures that range from a high of 79.9°F (26.6°C) to a low of 60.8°F (16°C).

What month has the most sunshine?

With an average of 9.9h of sunshine, July has the most sunshine of the year.

What is the month with the highest UV index?

With an average maximum UV index of 6, July is the month with the highest UV index.

What is the month with the shortest days?

With an average of 9h and 0min of daylight, December has the shortest days of the year.

Average temperature
Ontario, WI

Average temperature - Ontario, WI

The warmest month (with the highest average high temperature) is July (79.9°F).
The month with the lowest average high temperature is January (22.1°F).

The month with the highest average low temperature is July (60.8°F).
The coldest month (with the lowest average low temperature) is January (9.3°F).

Average pressure
Ontario, WI

Average pressure - Ontario, WI

The month with the highest atmospheric pressure is January (30.12"Hg).
The month with the lowest atmospheric pressure is June (29.9"Hg).

Average wind speed
Ontario, WI

Average wind speed - Ontario, WI

The windiest month (with the highest average wind speed) is April (9.3mph).
The calmest month (with the lowest average wind speed) is August (6.4mph).

Average humidity
Ontario, WI

Average humidity - Ontario, WI

The month with the highest relative humidity is January (90%).
The month with the lowest relative humidity is April (77%).

Average rainfall
Ontario, WI

Average rainfall - Ontario, WI

The wettest month (with the highest rainfall) is June (4.17").
The driest month (with the least rainfall) is January (1.1").

Average rainfall days
Ontario, WI

Average rainfall days - Ontario, WI

The month with the highest number of rainy days is May (17.5 days).
The month with the least rainy days is January (3.5 days).

Average snowfall
Ontario, WI

Average snowfall - Ontario, WI

The month with the highest snowfall is February (5.87").
The months with the least snowfall are June, July, August and September (0").

Average snowfall days
Ontario, WI

Average snowfall days - Ontario, WI

The month with the highest number of snowfall days is January (12.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

Average daylight / Average sunshine
Ontario, WI

Average daylight / Average sunshine - Ontario, WI

The month with the longest days is June (Average daylight: 15h and 24min).
The month with the shortest days is December (Average daylight: 9h and 0min).

The month with the most sunshine is July (Average sunshine: 9h and 54min).
The month with the least sunshine is January (Average sunshine: 3h and 0min).

Average sunshine days
Ontario, WI

Average sunshine days - Ontario, WI

The month with the most sunshine days is December (17.5 days).
The month with the least sunshine days is June (10.4 days).

Average UV index
Ontario, WI

Average UV index - Ontario, WI

The month with the highest UV index is July (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 1).

Average visibility
Ontario, WI

Average visibility - Ontario, WI

The months with the highest visibility are April, May, June, October and November (6mi).
The month with the lowest visibility is January (4mi).

Ontario, Wisconsin, USA

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