Climate and monthly weather forecast
Ontario, OR

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Weather in January

January, like December, in Ontario, Oregon, is a wintry winter month, with an average temperature fluctuating between 23.5°F (-4.7°C) and 36.1°F (2.3°C). Ontario's coldest period falls in January and December, when the average high-temperatures ascend to 36.1°F (2.3°C). Weather in January »

Weather in February

The last month of the winter, February, is another cold month in Ontario, Oregon, with an average temperature fluctuating between 42.4°F (5.8°C) and 29.1°F (-1.6°C). February's onset brings a subtle temperature rise, moving from a cold 36.1°F (2.3°C) in January to a still icy 42.4°F (5.8°C). Weather in February »

Weather in March

The first month of the spring, March, is a fresh month in Ontario, Oregon, with temperature in the range of an average low of 36.9°F (2.7°C) and an average high of 53.2°F (11.8°C). The arrival of March brings an increase in high-temperatures, moving from a cold 42.4°F (5.8°C) in February to a fresh 53.2°F (11.8°C). Weather in March »

Weather in April

April in Ontario, Oregon, is a refreshing spring month, with an average temperature fluctuating between 40.3°F (4.6°C) and 62.2°F (16.8°C). In Ontario, stepping into April brings a temperature increase, moving up from March's cool 53.2°F (11.8°C) to a refreshing 62.2°F (16.8°C). Weather in April »

Weather in May

The last month of the spring, May, is an agreeable month in Ontario, Oregon, with an average temperature ranging between max 72.1°F (22.3°C) and min 46.9°F (8.3°C). May's arrival sees a rise in the average high-temperature, jumping from April's comfortable 62.2°F (16.8°C) to an agreeable 72.1°F (22.3°C). Weather in May »

Weather in June

June, the first month of the summer in Ontario, is a warm month, with an average temperature fluctuating between 54.1°F (12.3°C) and 81°F (27.2°C). With the onset of June, Ontario observes a minor temperature ascent, with the average high-temperature adjusting from May's pleasant 72.1°F (22.3°C) to a warm 81°F (27.2°C). Weather in June »

Weather in July

July in Ontario, Oregon, is a hot summer month, with temperature in the range of an average high of 93.2°F (34°C) and an average low of 62.2°F (16.8°C). Ontario's warmest month, July, generally records average temperatures ranging from a high of 93.2°F (34°C) to a low of 62.2°F (16.8°C). Weather in July »

Weather in August

The last month of the summer, August, is another tropical month in Ontario, Oregon, with an average temperature varying between 91.9°F (33.3°C) and 62.1°F (16.7°C). Ontario indicates an average high-temperature of a still tropical 91.9°F (33.3°C) in August, showing minor variation from July's 93.2°F (34°C). Weather in August »

Weather in September

The first month of the autumn, September, is also a moderately hot month in Ontario, Oregon, with an average temperature varying between 80.6°F (27°C) and 55.2°F (12.9°C). September's onset brings a slight change in high-temperatures, falling from a tropical 91.9°F (33.3°C) in August to a warm 80.6°F (27°C). Weather in September »

Weather in October

October, the same as September, is another refreshing autumn month in Ontario, Oregon, with an average temperature ranging between min 43.7°F (6.5°C) and max 62.6°F (17°C). October's onset witnesses a marked shift in the average high-temperature, moving from a warm 80.6°F (27°C) in September to a refreshing 62.6°F (17°C). Weather in October »

Weather in November

The last month of the autumn, November, is also a frosty month in Ontario, Oregon, with an average temperature varying between 32.7°F (0.4°C) and 48.2°F (9°C). With the beginning of November, Ontario's average high-temperature experiences a significant decrease, moving from a refreshing 62.6°F (17°C) in October to a frosty 48.2°F (9°C). Weather in November »

Weather in December

The first month of the winter, December, is also a wintry month in Ontario, Oregon, with an average temperature ranging between min 23°F (-5°C) and max 36.1°F (2.3°C). During January and December, Ontario registers its lowest temperatures, averaging a high of 36.1°F (2.3°C). Weather in December »

Frequently asked questions

What is the coldest month?

Ontario experiences the lowest of its temperatures in January and December, when the average high-temperatures rise to 36.1°F (2.3°C).

What is the most humid month?

January is the most humid month in Ontario, with an average relative humidity of 82%.

How much does it rain?

Throughout the year, in Ontario, Oregon, there are 84.9 rainfall days, and 9.29" (236mm) of precipitation is accumulated.

When does it snow?

Months with snowfall are January through April, November and December.

How much does it snow?

In Ontario, during the entire year, snow falls for 21.8 days and aggregates up to 12.56" (319mm) of snow.

What are the months with the lowest UV index?

January, February, November and December, with an average maximum UV index of 2, are months with the lowest UV index.

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 MST to MDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from MDT to MST.

When it does not snow?

In Ontario, 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 24min of daylight.

What is the warmest month?

In Ontario, the average temperatures in July are the highest, with a peak at 93.2°F (34°C) and a low of 62.2°F (16.8°C).

What is the driest month?

July is the month with the least rainfall. Rain falls for 2.5 days and accumulates 0.08" (2mm) of precipitation.

What month has the most sunshine?

With an average of 12.1h of sunshine, July has the most sunshine of the year.

When is the highest UV index?

With an average maximum UV index of 7, July is the month with the highest UV index.

What is the least humid month?

The least humid month is August, with an average relative humidity of 29%.

What is the rainiest month?

December is the month with the most rainfall. Rain falls for 8.9 days and accumulates 1.57" (40mm) of precipitation.

What is the snowiest month?

The month with the most snowfall is December, when snow falls for 7.4 days and typically aggregates up to 5.35" (136mm) of snow.

What is the month with the shortest days?

The month with the shortest days is December, with an average of 9h and 0min of daylight.

What is the month with the least sunshine?

With an average of 5.1h of sunshine, December has the least sunshine of the year.

Average temperature
Ontario, OR

Average temperature - Ontario, OR

The warmest month (with the highest average high temperature) is July (93.2°F).
The months with the lowest average high temperature are January and December (36.1°F).

The month with the highest average low temperature is July (62.2°F).
The coldest month (with the lowest average low temperature) is December (23°F).

Average pressure
Ontario, OR

Average pressure - Ontario, OR

The month with the highest atmospheric pressure is January (30.24"Hg).
The months with the lowest atmospheric pressure are June and August (29.92"Hg).

Average wind speed
Ontario, OR

Average wind speed - Ontario, OR

The windiest month (with the highest average wind speed) is April (6.5mph).
The calmest month (with the lowest average wind speed) is January (3.9mph).

Average humidity
Ontario, OR

Average humidity - Ontario, OR

The month with the highest relative humidity is January (82%).
The month with the lowest relative humidity is August (29%).

Average rainfall
Ontario, OR

Average rainfall - Ontario, OR

The wettest month (with the highest rainfall) is December (1.57").
The driest month (with the least rainfall) is July (0.08").

Average rainfall days
Ontario, OR

Average rainfall days - Ontario, OR

The month with the highest number of rainy days is March (13.3 days).
The month with the least rainy days is August (1.8 days).

Average snowfall
Ontario, OR

Average snowfall - Ontario, OR

The month with the highest snowfall is December (5.35").
The months with the least snowfall are May, June, July, August, September and October (0").

Average snowfall days
Ontario, OR

Average snowfall days - Ontario, OR

The month with the highest number of snowfall days is December (7.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average daylight / Average sunshine
Ontario, OR

Average daylight / Average sunshine - Ontario, OR

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: 12h and 6min).
The month with the least sunshine is December (Average sunshine: 5h and 6min).

Average sunshine days
Ontario, OR

Average sunshine days - Ontario, OR

The month with the most sunshine days is July (27.7 days).
The month with the least sunshine days is February (15.2 days).

Average UV index
Ontario, OR

Average UV index - Ontario, OR

The month with the highest UV index is July (UV index 7).
The months with the lowest UV index are January, February, November and December (UV index 2).

Average visibility
Ontario, OR

Average visibility - Ontario, OR

The months with the highest visibility are February, March, April, May, June, July, August, September, October and November (6mi).
The months with the lowest visibility are January and December (5mi).

Ontario, Oregon, USA

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