Natural Disasters in Tennessee: What Is the Risk?
Nearly 7 million people live in Tennessee. Many of these people have experienced natural disasters in the state firsthand or had to evacuate because of disasters. However, many Tennessee residents don’t realize just how many types of natural disasters can occur in the state.
This analysis goes over what natural disasters occur in Tennessee, the worst natural disasters to hit the state since 2000, and what residents can do to prepare.
Is Tennessee At Risk of Natural Disasters?
Tennessee has a medium risk of natural disasters compared to the rest of the United States. Excluding COVID, Tennessee has had 49 disaster declarations since 2000. Of these, 38 were declared major disasters.
Tennessee is also frequently hit by natural disasters, which cause more than $1 billion in damages. Since 2000, more than 71 separate $1-billion events have affected Tennessee. Most of these were severe storms.
Worst Natural Disasters in Tennessee By Cost (Since 2000)
- Hurricane Katrina 2005: $190 billion
- Hurricane Harvey 2017: $151.3 billion
- Hurricane Ida 2021: $80.2 billion
- 2012 Drought and Heat Wave: $39.3 billion
- Hurricane Ivan 2004: $32.2 billion
Worst Natural Disasters in Tennessee By Deaths (Since 2000)
- Hurricane Katrina 2005: 1,833 deaths
- Southeast/Ohio Valley/Midwest Tornadoes 2011: 321 deaths
- February 2021 Winter Storm and Cold Wave: 262 deaths
- May 2011 Tornado Outbreak: 177 deaths
- Spring-Fall 2000 Drought and Heat Wave: 140 deaths
*Cost and death tolls are for the entire disaster, including in other states affected.
Most Common Natural Disasters in Tennessee
Tennessee is located on the New Madrid Seismic Zone (NMSZ). While this zone doesn’t have earthquakes as frequently as those in the Western part of the USA, it has the potential for large, damaging earthquakes of up to 7.6 magnitude.
The NMSZ has approximately 200 earthquakes each year. Most of these are too small to be felt. However, there is an earthquake of magnitude 4.0 or greater in the zone approximately once every 18 months. A magnitude 5.0 quake occurs approximately once every 10 years.
The western part of Tennessee is particularly at-risk for damaging earthquakes, but quakes could affect anywhere in the state.
One of the worst earthquakes to occur in Tennessee was a magnitude 7.0 quake in 1865 near Memphis. In the past 100 years, Tennessee has had at least six magnitude 4.0 or higher earthquakes.
Tennessee has over 49,000 miles of streams and rivers. The state often has heavy rains, including rains from nearby hurricanes or tropical storms. The rain can cause rivers to swell, resulting in widespread flooding.
Because of climate change, the frequency of heavy rainfall events is expected to increase in Tennessee. By 2050, an estimated 12.1% of all properties in the state will be at risk of flooding.
Tennessee Flood Stats
- 383,200 properties at substantial risk in 2020
- 495,300 properties at risk by 2050
- 395,600 properties at substantial risk by 2050
- 135,500 properties at almost certain risk by 2050
- 157,100 FEMA flood damage claims since 2000
Which Areas of Tennessee Are Most At-Risk to Flooding?
Floods can occur in all parts of Tennessee, but some areas of the state are particularly at-risk. Below are the areas of Tennessee with the most significant percentage of properties likely to experience flooding (based on 2020 calculations).
- Chattanooga: 42%
- Kingston: 41%
- Louisville: 40%
- Dayton: 39%
- Erwin: 39%
- Middle Valley: 38%
- East Ridge: 35%
- Lenoir City: 32%
- Pigeon Forge: 32%
In addition to these areas, there are many major cities in Tennessee where thousands of properties are at risk. This includes over 33,000 properties in Nashville-Davidson and over 32,000 properties in Memphis.
Tennessee has an average of 28 tornadoes per year. Many of these tornadoes are strong and destructive. While Tennessee has never had an F5 tornado, it has had many F4 tornadoes. The most fatal event was a cluster of F4 and F3 tornadoes on March 3rd, 2020. These tornadoes killed 24 people and injured over 300 people.
Since 2000, approximately 140 people have died from tornadoes in Tennessee, and over 1,400 have been injured. Tornadoes in Tennessee have also caused over $2 billion in property and crop damages.
It isn’t common for people to have basements in Tennessee, so residents should ensure they have an above-ground storm shelter and an emergency radio with tornado alerts set.
4. Winter Storms
Tennessee generally has very mild winters and only averages 4.61 inches of snowfall per season. However, the state does sometimes have snowstorms. These snowstorms can catch residents unprepared. Vehicle accidents are a big problem for people not used to driving in snow.
Winter storms in Tennessee can also cause power outages, leaving people without a way to heat their homes. Improper use of generators or indoor heaters can lead to carbon monoxide poisoning.
5. Heat Waves and Droughts
Tennessee is part of the “Extreme Heat Belt” in the central United States. This region is very at risk of what the National Weather Service calls “dangerous” and “extremely dangerous” heat days. A “dangerous” heat day is defined as one where the heat index is 103F, and an “extremely dangerous” day has a heat index of 124F or above, which is considered unsafe for all people for any amount of time.
By 2053, Extreme Danger days will affect an estimated 107 million people in the Extreme Heat Belt. In Tennessee, more than 200,000 are considered vulnerable to extreme heat.
Currently, Tennessee sees an average of 10 days per year of dangerous heat. However, this number is going to increase over the next few decades. By 2050, Tennessee is expected to see 55 dangerous heat days per year.
The risk of dangerous heat days is expected to increase throughout Tennessee. However, Tipton County is especially at-risk. By 2053, Tipton is expected to have 64 dangerous heat days per year.
Heat waves are often accompanied by droughts, which can have a huge economic toll on Tennessee’s agricultural communities and increase the risk of wildfires.
Tennessee is one of the most at-risk states for wildfires in the region. While the state doesn’t see many wildfires yearly, the wildfires tend to be very large and destructive. Each year, an average of 100 buildings will be destroyed by wildfires.
Since 2000, Tennessee has declared disaster 10 times because of wildfires. One of the worst wildfires in the state’s recent history was the 2016 Southeast wildfire. A combination of dry conditions and hurricane-force winds cause a massive firestorm in the Gatlinburg region. The year 2022 was also a particularly bad year for wildfires in Tennessee.
Luckily, the state does practice controlled burning to minimize damage. Most of the state’s wildfires occur during late winter to early spring when there is lots of dry debris on the ground. Careless burning of waste is the leading cause of wildfires in the state.
Because of climate change, the risk of wildfires in Tennessee is growing. By 2050, an estimated 65% of all properties in the state will be at risk of wildfire.
Tennessee Wildfire Stats
- Average number of wildfires per year: 750
- Average number of acres burned per year: 17,000
- Percentage of state covered by forests: 52%
- Number of properties currently at risk of wildfire: 1,879,314