What's Your Home's Flood or Wildfire Danger? This Site Will Tell You

By: Jennifer Walker-Journey  | 
Hurricane Ian flooding
A flooded street is filled with submerged cars in the Orlovista neighborhood of Orlando after Hurricane Ian ripped through Florida, dumping nearly a foot of rain in 12 hours on central and eastern parts of the state. BRYAN R. SMITH/AFP via Getty Images

Weather-related events have always posed threats to property. Homeowners often consider these risks before buying. But if they rely on data from the Federal Emergency Management Agency (FEMA), they may not be getting the full picture. That's because FEMA doesn't take into consideration the impact climate change will have on weather patterns throughout the life of their mortgage.

Global warming contributes to extreme weather events around the globe, causing more floods, tornadoes, wildfires and hurricanes. It's also blamed for an increase in extreme heat waves, which cause droughts and dried-out vegetation. Those same dry conditions create a ripe canvas for forest fires.


Multiple studies have shown that climate change has lengthened wildfire seasons and frequencies, and burned areas due to warmer springs, longer summer dry seasons, and drier soils and vegetation. As a result, homes are more vulnerable to destructive natural events than ever before.

Is Your Home at Risk?

But just how at risk is your home or one you're considering buying?

"Just like every home is assessed for safety, structural integrity and other crucial elements during an inspection in the homebuying process, having a full understanding of a home's climate risk is a critically important element for a homebuyer to be aware of," says Michael Lopes, communications director for First Street Foundation, a nonprofit research group based in Brooklyn, New York. First Street was founded in 2017 to rally experts across a variety of disciplines to quantify and communicate the physical risks of extreme weather to the public.


Lopes says homeowners should consider weather risks when they're shopping for a home, just like they consider schools, safety, public utilities and structural soundness. But this information is hard to find. "This data is available, but it languishes in peer-reviewed journals and scientific papers that [is] mostly indecipherable to non-climate scientists," Lopes explains.

So First Street created RiskFactor.com, to give consumers access the data. "RiskFactor.com is the one-stop-shop for understanding those risks and how they're changing alongside a changing climate," he says.

The site began providing flood risk information "as it is the most expensive natural disaster directly linked to climate change," Lopes says. The team worked to model risk at the property parcel level and integrated the findings into Flood Factor. The site vertical provides property-specific, peer-reviewed, climate-adjusted flood risk data for every home in America. Just plug in your address and you'll get detailed information about your home's risk for flooding in easy-to-understand language.

In 2020, the team added a Fire Factor assessment to gauge properties' wildfire risks, followed by Heat Factor, which measures extreme heat risks. These three assessments all becameRisk Factor, which First Street then shared with real estate sites such as Realtor, Redfin, Compass, Estately and Crexi.

"Our hope is that by making this information publicly available and easy to understand, we can help American homeowners and buyers protect what is probably their largest financial investment and understand how climate will impact it over the course of their mortgage," Lopes says.

Dixie Fire
A burned-out car sits in front of a home that was destroyed by the Dixie Fire in Indian Falls, California in July 2021. At the time, the Dixie Fire was the largest wildfire in California.
Justin Sullivan/Getty Images


How Does Risk Factor Data Differ From Federal Data?

Mortgage and insurance companies rely on various data to assess a property's risk for natural disasters. For flood risk, the primary source is FEMA flood maps. Like on Risk Factor, consumers can plug in their address and see areas with flood risks within their community. But unlike Risk Factor, the FEMA data isn't property specific.

FEMA's flood maps are created by FEMA agents and a floodplain administrator who work with local engineers and surveys to collect data on flood zones. Flood zones are primarily determined by the history of flooding in the area and are rated according to the probability of annual flooding. FEMA maps do not consider how the climate is expected to change in the future and how that will impact weather events.


Risk Factor, however, uses current climate data, maps and precipitation, and includes areas that FEMA hasn't mapped. This model identifies the likelihood of flooding by recreating dozens of past hurricanes, tropical storms, nor'easters and major inland flood events. The Risk Factor model also calculates the current probability of tidal, storm surge, pluvial (rainfall) and fluvial (riverine) flooding for individual homes and properties. The resulting analysis reveals a far different picture than what FEMA maps paint.

For example, FEMA classifies 8.7 million properties as having substantial flood risk or being within special flood hazard areas. Risk Factor, on the other hand, after adjusting for future environmental factors like changing sea levels, warming sea surface and atmospheric temperatures and changing precipitation patterns, finds the number about 70 percent higher — with 14.6 million properties at the same level of risk.

Another example is wildfire risk. States prone to wildfire typically assess a property's wildfire risk based on factors such as topography, vegetation, wind patterns and how accessible a home is to firefighters in the event of a fire. According to Verisk Analytics, a data analytics and risk assessment firm, 4.5 million U.S. homes are identified at high or extreme risk of wildfire.

In determining a property's wildfire risk, Risk Factor digs deeper. It uses data on historical wildfire occurrences to inform where wildfires may occur based on the Fire Occurrence Database developed by the United States Forest Service. But it also considers climate changes. The tool identifies more than 10 million U.S. properties at major risk to extreme risk of wildfire. Overall, Risk Factor found that 71.8 million homes have some level of wildfire risk in 2022, growing to 79.8 million by 2050 due to the changing climate.

Risk Factor also predicts the frequency, duration and intensity of extremely hot days will change over the next 30 years. Its model shows that 50 counties in the U.S. with more than 8 million residents will experience temperatures above 125 degrees Fahrenheit (51.6 degrees Celsius) in 2023 and by 2053, a total of 1,023 counties are expected to exceed 125 degrees, affecting 107.6 million Americans.

Research shows that extreme heat increases the risk of other natural disasters including drought. Hot, dry conditions can, in turn, create an environment ripe for wildfire. Beyond Risk Factor, First Street Foundation and the Research Lab team continue to better understand climate risk, its consequences and possible solutions. Take a look at some of the nonprofit's recently published research here.

heat factor map
This hyper-local map from Risk Factor shows an extremely granular understanding of heat risks. It was created using climate-adjusted predictions for the monthly averaged daily maximum temperature for the hottest month of the year over a seven year period.
Risk Factor