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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 days
- Average daylight
- Average sunshine
- Average sunshine days
- Average UV index
- Average cloud cover
- Average visibility
The luxurious residential estate in Ontario, California, with a scenic background of a hilly landscape
Weather in January
January, like December, in Ontario, California, is another enjoyable winter month, with temperature in the range of an average high of 64.6°F (18.1°C) and an average low of 46.8°F (8.2°C). At the onset of January, Ontario records an average high-temperature of a still enjoyable 64.6°F (18.1°C), showing little deviation from the preceding month. Weather in January »
Weather in February
The last month of the winter, February, is another comfortable month in Ontario, California, with an average temperature fluctuating between 64°F (17.8°C) and 45.7°F (7.6°C). As Ontario transitions from January to February, the average high-temperatures adjust to a still enjoyable 64°F (17.8°C), nearly the same as the previous 64.6°F (18.1°C). Weather in February »
Weather in March
March, the first month of the spring in Ontario, is an agreeable month, with an average temperature ranging between max 68.4°F (20.2°C) and min 46.9°F (8.3°C). Transitioning into March, Ontario experiences an average high-temperature of an agreeable 68.4°F (20.2°C), marking a minor shift from the preceding month. Weather in March »
Weather in April
April, the same as March, in Ontario, California, is an agreeable spring month, with temperature in the range of an average low of 50.2°F (10.1°C) and an average high of 72.9°F (22.7°C). April's weather displays an average high-temperature of a still pleasant 72.9°F (22.7°C), slightly varied from March's 68.4°F (20.2°C). Weather in April »
Weather in May
May, the last month of the spring in Ontario, is a moderately hot month, with temperature in the range of an average high of 76.6°F (24.8°C) and an average low of 53.6°F (12°C). Ontario's average high-temperature in May is a moderately hot 76.6°F (24.8°C), indicating a subtle variation from April. Weather in May »
Weather in June
June, the first month of the summer in Ontario, is still a warm month, with an average temperature fluctuating between 84°F (28.9°C) and 58.5°F (14.7°C). As June arrives, Ontario's weather shows a minor increase in high-temperatures, edging from May's 76.6°F (24.8°C) to a still moderately hot 84°F (28.9°C). Weather in June »
Weather in July
July in Ontario, California, is a hot summer month, with temperature in the range of an average high of 90°F (32.2°C) and an average low of 64.8°F (18.2°C). The shift from June to July sees a slight increase in the average high-temperature, transitioning from a warm 84°F (28.9°C) to a hot 90°F (32.2°C). Weather in July »
Weather in August
August, the last month of the summer in Ontario, is another hot month, with temperature in the range of an average high of 91°F (32.8°C) and an average low of 65.8°F (18.8°C). August is the warmest month of the year, registering average temperatures as high as 91°F (32.8°C) and as low as 65.8°F (18.8°C). The average heat index in August is appraised at a tropical 93.2°F (34°C). Weather in August »
Weather in September
September, the first month of the autumn in Ontario, is still a hot month, with temperature in the range of an average low of 63.5°F (17.5°C) and an average high of 88.2°F (31.2°C). Upon the onset of September, Ontario witnesses an average high-temperature of a still tropical 88.2°F (31.2°C), showing a close resemblance to the prior month. Weather in September »
Weather in October
October, like September, in Ontario, California, is another warm autumn month, with an average temperature varying between 57.9°F (14.4°C) and 79°F (26.1°C). A decrease in the average high-temperature is observed during October, shifting from a tropical 88.2°F (31.2°C) in September to a warm 79°F (26.1°C). Weather in October »
Weather in November
The last month of the autumn, November, is another pleasant month in Ontario, California, with an average temperature varying between 70.7°F (21.5°C) and 50.9°F (10.5°C). November's arrival signals a moderate reduction in the average high-temperature, easing from a warm 79°F (26.1°C) in October to a pleasant 70.7°F (21.5°C). Weather in November »
Weather in December
December, the first month of the winter in Ontario, is still a refreshing month, with an average temperature varying between 45.5°F (7.5°C) and 62.1°F (16.7°C). Ontario's coldest month, December, generally records average temperatures ranging from a high of 62.1°F (16.7°C) to a low of 45.5°F (7.5°C). Weather in December »
Updated: Feb 9, 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
How many days does it rain in Ontario?
Throughout the year, there are 49.6 rainfall days, and 7.8" (198mm) of precipitation is accumulated.
When it does not snow in Ontario?
In Ontario, snow does not fall in January, March through December.
How many days does it snow in Ontario?
In Ontario, during the entire year, snow falls for 0.1 days.
What is the wettest month in Ontario?
The month with the most rainfall in Ontario, California, is February, when the rain falls for 6 days and typically aggregates up to 1.77" (45mm) of precipitation.
When does it snow in Ontario?
February is the only month when snow falls.
What is the snowiest month in Ontario?
February has the most snowfall days of the year. Snow falls for 0.1 days.
What are the months with the least sunshine in Ontario?
The months with the least sunshine are February and December, with an average of 6.9h of sunshine.
What is the most humid month in Ontario?
March and May, with an average relative humidity of 54%, are most humid months.
When is Daylight Saving Time (DST) in Ontario?
On Sunday, March 10. 2024, at 2:00 am, Daylight Saving Time starts in Ontario, California, and the time zone changes from PST to PDT. Daylight Saving Time ends Sunday, November 3. 2024, at 2:00 am, and the time zone reverts from PDT to PST.
What is the driest month in Ontario?
The month with the least rainfall is June, when the rain falls for 1.2 days and typically collects 0.04" (1mm) of precipitation.
When are the longest days in Ontario?
June has the longest days of the year, with an average of 14h and 24min of daylight.
What month has the most sunshine in Ontario?
With an average of 12.1h of sunshine, July has the most sunshine of the year in Ontario, California.
What are the months with the highest UV index in Ontario?
July and August, with an average maximum UV index of 7, are months with the highest UV index.
What month is the hottest in Ontario?
Ontario records the warmest temperatures in August, averaging a high of 91°F (32.8°C) and a low of 65.8°F (18.8°C).
What is the least humid month in Ontario?
August is the least humid month, with an average relative humidity of 42%.
What month is the coldest in Ontario?
December, noted for its average high-temperature of 62.1°F (16.7°C) and an average low-temperature of 45.5°F (7.5°C), is considered the coldest month in Ontario.
What is the month with the shortest days in Ontario?
December has the shortest days of the year in Ontario, California, with an average of 9h and 54min of daylight.
What is the month with the lowest UV index in Ontario?
With an average maximum UV index of 3, December is the month with the lowest UV index in Ontario.
Average temperature
Ontario, CA
The warmest month (with the highest average high temperature) is August (91°F).
The month with the lowest average high temperature is December (62.1°F).
The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is December (45.5°F).
Average pressure
Ontario, CA
- Average pressure in January:
30.1"Hg - Average pressure in February:
30.05"Hg - Average pressure in March:
30.02"Hg - Average pressure in April:
29.95"Hg - Average pressure in May:
29.91"Hg - Average pressure in June:
29.86"Hg
- Average pressure in July:
29.89"Hg - Average pressure in August:
29.88"Hg - Average pressure in September:
29.88"Hg - Average pressure in October:
29.94"Hg - Average pressure in November:
30.03"Hg - Average pressure in December:
30.07"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.86"Hg).
Average wind speed
Ontario, CA
- Average wind speed in January:
5.3mph - Average wind speed in February:
5mph - Average wind speed in March:
5.2mph - Average wind speed in April:
5.8mph - Average wind speed in May:
5.8mph - Average wind speed in June:
5.4mph
- Average wind speed in July:
5.1mph - Average wind speed in August:
4.7mph - Average wind speed in September:
4.4mph - Average wind speed in October:
4.8mph - Average wind speed in November:
5mph - Average wind speed in December:
5.2mph
The windiest months (with the highest average wind speed) are April and May (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.4mph).
Average humidity
Ontario, CA
The months with the highest relative humidity are March and May (54%).
The month with the lowest relative humidity is August (42%).
Average rainfall
Ontario, CA
- Average rainfall in January:
1.18" - Average rainfall in February:
1.77" - Average rainfall in March:
0.79" - Average rainfall in April:
0.71" - Average rainfall in May:
0.24" - Average rainfall in June:
0.04"
- Average rainfall in July:
0.16" - Average rainfall in August:
0.12" - Average rainfall in September:
0.12" - Average rainfall in October:
0.24" - Average rainfall in November:
0.75" - Average rainfall in December:
1.69"
The wettest month (with the highest rainfall) is February (1.77").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days
Ontario, CA
- Average rainfall days in January:
5.4 days - Average rainfall days in February:
6 days - Average rainfall days in March:
7.1 days - Average rainfall days in April:
5.7 days - Average rainfall days in May:
3.8 days - Average rainfall days in June:
1.2 days
- Average rainfall days in July:
2.8 days - Average rainfall days in August:
1.7 days - Average rainfall days in September:
2.5 days - Average rainfall days in October:
3 days - Average rainfall days in November:
4 days - Average rainfall days in December:
6.4 days
The month with the highest number of rainy days is March (7.1 days).
The month with the least rainy days is June (1.2 days).
Average snowfall days
Ontario, CA
- Average snowfall days in January:
0 days - Average snowfall days in February:
0.1 days - Average snowfall days in March:
0 days - Average snowfall days in April:
0 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 days - Average snowfall days in November:
0 days - Average snowfall days in December:
0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight / Average sunshine
Ontario, CA
- Average daylight in January:
10h and 1min - Average daylight in February:
11h and 0min - Average daylight in March:
12h and 0min - Average daylight in April:
13h and 1min - Average daylight in May:
13h and 5min - Average daylight in June:
14h and 2min
- Average daylight in July:
14h and 1min - Average daylight in August:
13h and 2min - Average daylight in September:
12h and 2min - Average daylight in October:
11h and 2min - Average daylight in November:
10h and 2min - Average daylight in December:
9h and 5min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in January:
7h and 0min - Average sunshine in February:
6h and 5min - Average sunshine in March:
9h and 0min - Average sunshine in April:
11h and 2min - Average sunshine in May:
11h and 5min - Average sunshine in June:
12h and 0min
- Average sunshine in July:
12h and 1min - Average sunshine in August:
12h and 0min - Average sunshine in September:
10h and 4min - Average sunshine in October:
8h and 5min - Average sunshine in November:
7h and 2min - Average sunshine in December:
6h and 5min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 54min).
Average sunshine days
Ontario, CA
- Average sunshine days in January:
24.6 days - Average sunshine days in February:
21.5 days - Average sunshine days in March:
23.6 days - Average sunshine days in April:
23.8 days - Average sunshine days in May:
26 days - Average sunshine days in June:
28.2 days
- Average sunshine days in July:
25.4 days - Average sunshine days in August:
26.8 days - Average sunshine days in September:
25.4 days - Average sunshine days in October:
26.5 days - Average sunshine days in November:
25.5 days - Average sunshine days in December:
23.2 days
The month with the most sunshine days is June (28.2 days).
The month with the least sunshine days is February (21.5 days).
Average UV index
Ontario, CA
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover
Ontario, CA
The month with the most cloud cover is December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility
Ontario, CA
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
Ontario, California, USA
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