Ontario, CA Weather - Forecast & Monthly Averages

TEMPERATURE	65
HUMIDITY	52
PRESSURE	101630
WIND COND.	250 14.8

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Weather Quick Facts

The highest monthly average temperature in Ontario for August is 77.8 degrees
The lowest monthly average temperature in Ontario for December is 54.5 degrees
The most monthly precipitation in Ontario occurs in December with 2.6 inches
The air quality index in Ontario is 111% worse than the national average
The pollution index in Ontario is 736% worse than the national average

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Ontario Average Temperature

In the event that the weather data was unavailable for this city, estimates based upon nearby cities were used.
Month	Temp. _(min)	Temp. _(max)	Temp. _(avg)	Precipitation
January	44°F	69°F	56°F	2.3"
February	45°F	70°F	57°F	2.0"
March	48°F	74°F	60°F	1.2"
April	51°F	77°F	62°F	0.7"
May	55°F	81°F	66°F	0.4"
June	60°F	88°F	72°F	0.0"
July	65°F	94°F	77°F	0.1"
August	65°F	95°F	78°F	0.0"
September	64°F	93°F	76°F	0.2"
October	57°F	84°F	69°F	0.4"
November	49°F	77°F	62°F	0.6"
December	43°F	68°F	55°F	2.6"

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Ontario air quality index & pollution index

In the event that the air quality/pollution data was unavailable for this city, estimates based upon nearby cities were used.
Index	Ontario	California	National
Air quality index	89	55	42
Pollution index	22,790,900	10,473,190	2,726,193

Ontario air quality information

Measurement	Total
Days measured	365
Days with good air quality	42
Days with moderate air quality	178
Days w/ poor A.Q. for sensitive groups	79
Days with unhealthy air quality	58

Ontario air quality information

Pollutant	Total
Arsenic	0.060%
Benzene	0.190%
Carbon Tetrachloride	0.010%
Lead	0.220%
Mercury	0.230%

Average monthly Ontario temperature with heat index

Ontario monthly precipitation with daily maximum

Ontario monthly snow depth with daily maximum

Ontario monthly wind speed information

Nearby cities with good air quality

City	Population	Air Quality Index	National Avg.
Azusa, CA	49,584	72	44.0%
South San Jose Hills, CA	19,104	72	44.0%
Citrus, CA	10,105	72	44.0%
West Covina, CA	105,808	72	44.0%
Yorba Linda, CA	68,103	89	78.0%
Ontario, CA	178,194	89	78.0%

Cities with similar population

City	Population	Air Quality Index	National Avg.
Rancho Cucamonga, CA	178,060	89	78.0%
Santa Rosa, CA	178,391	34	32.0%
Providence, RI	179,472	44	12.0%
Newport News, VA	179,582	40	20.0%
Oshawa, ON	176,009	n/a
Ontario, CA	178,194	89	78.0%

Source: The Ontario, CA weather data displayed above is derived from the NOAA (National Oceanic and Atmospheric). Air quality and pollution data is derived from the EPA (United States Environmental Protection Agency). Air quality and pollution levels measured in a particular area may not be representative of the entire county.