Ratings represent risk relative to the contiguous United States. 100 is the highest risk for the hazard and 1 is the lowest for the U.S., but does not indicate no risk. Flood and fire are rated based on the buildings in Ontario exposed to these hazards. See hazard sections below and check your address for details.
Heat risk in Ontario, CA is high. Drought and precipitation risk is significant. About 42% of buildings in Ontario, CA are at risk of flooding, and the risk level for these buildings is significant. About 12% of buildings in Ontario, CA are at risk of wildfire, and the risk level for these buildings is high.
Fire and flood risk can vary significantly for individual properties within a city. Check your address for detailed heat, storm, fire, drought, and flood risk through 2050.
The number of the hottest days in Ontario is projected to keep increasing.
In a typical year between 1985-2005, people in Ontario, CA experienced about 7.0 days above 100.1ºF in a year. By 2050, people in Ontario are projected to experience an average of about 30.0 days per year over 100.1ºF.
Climate change is increasing the frequency and intensity of heat waves, even in places with cooler average temperatures. See more information on heat risk. Everyone can take steps to reduce their risks from extreme heat.
The recent average water stress in Ontario is moderately low and projected to increase through 2050.
The Santa Ana watershed, which contains Ontario, CA, has experienced 811 weeks (71% of weeks) since 2000 with some of its area in drought of any level, and 253 weeks (22% of weeks) since 2000 with some of its area in Extreme or Exceptional drought. Source: National Drought Monitor.
Climate change is increasing the risk of drought. Water stress (the ratio of water demand to supply) depends on how water utilities source water and their plans to adapt to climate change. Property owners can also take steps to reduce their risks from drought.
The amount of precipitation during the most extreme days in Ontario is projected to remain about the same through 2050.
An extreme storm for Ontario, CA is a 48-hour rainfall total greater than 0.6 inches. Historically, about 10.0" of rain (or the equivalent in snow) fell over about 9 storms each year. By 2050, about 10.2" of rain are projected over about 9 storms each year. The annual precipitation in Ontario, CA is projected to remain about the same, 14.5".
Extreme precipitation in any form can pose significant risks. Climate change increases the potential for extreme rainfall or snowfall because warmer air can hold more water vapor. See more information on storm risk. Property owners can take steps to reduce their risks from extreme precipitation.
Buildings at risk in Ontario average about a 27.0% chance of a flood about 10.0 inches deep over 30 years.
Of 65 census tracts in Ontario, CA, there are 33 where more than half of buildings have significant risk from surface (pluvial) flooding and riverine (fluvial) flooding.Property owners can check a specific address for flood risk including FEMA flood zone, then take steps to reduce their vulnerability to flooding damage.
Climate change is increasing inland and coastal flooding risk due to sea level rise and increasing chances of extreme precipitation. See more information on flooding risk.
The risk on the most dangerous fire weather days in Ontario is very high. The number of these days per year is expected to increase through 2050.
Of 65 census tracts in Ontario, CA, there are 19 where more than a quarter of buildings have significant fire risk, and 12 where more than half of buildings have significant fire risk. Property owners can take steps to mitigate their risks from wildfires.
Fire risk) depends on proximity to vegation: densely developed urban areas have a much lower risk of burning than areas adjacent to wildland. Climate change increases risks from wildfire by creating hotter, drier conditions for fires to spread. ClimateCheck ratings of fire risk are based on projected weather conditions and U.S. Forest Service models simulating fire behavior.
Mitigating climate change, by eliminating our emissions into the atmosphere and reducing our strain on the environment, and adapting to our changing planet are both vital to our well-being.
The risks presented on this page reflect averages for Ontario, CA and can vary for individual properties. Check your address and request a report describing risks to your property and in your area.
Check our free report for tips on protecting your home from hazards.
Green infrastructure is a category of nature-based solutions for managing increasing precipitation. Find resources for individuals and municipalities through the EPA Soak Up the Rain initiative.
Planting trees and vegetation helps reduce extreme heat in urban environments. Cool pavements can also help. Search the Heat Island Community Actions Database to see what some municipalities have been doing to reduce extreme heat risk.
Read more about building resilience for communities: U.S. Climate Resilience Toolkit
Use the Common Cause tool to find your representatives, how to contact them, and information about political contributions and bills they have introduced.
Reducing emissions is necessary and possible across the globe and in every part of our society. Learn more with the Project Drawdown introduction to climate solutions.
Estimate your emissions with the CoolClimate calculator.