Although you might assume that winter is the most accident-prone season, more than 72% of U.S. drivers – roughly 170 million – live in states where fall is the peak season for accident damage, according to Carfax data.
As for why more accidents happen in the fall, seasonal hazards like an increase in deer due to mating season certainly play a role. But experts say the season's weather conditions and diminishing daylight are overwhelming the cause, negatively impacting visibility and the control drivers have over their vehicles.
Fall means shorter days, and that means more driving in the dark, when drivers are twice as likely to have an accident as in daylight. Half of U.S. accidents happen in the dark, but those hours account for only 25 percent of travel, Carfax noted.
Slick surfaces are also at play. Wet leaves brought down by storms can be as slippery as ice. Braking on wet leaves can make a car travel more than twice as far as braking on a dry road.
Of course, not every state gets the same weather in the fall. To determine the most dangerous states where fall weather may affect drivers' safety, injury lawyers Anidar & Levine conducted a study using fatal crash and weather data from the National Highway Traffic Safety Administration.
The study produced a ranking by compiling historical weather data to reveal the number of days which were raining, snowing, foggy, sleeting or severely windy, and correlating this with the number of fatal traffic accidents occurring on that day.
It may come as no surprise that Alaska, renowned for its cold temperatures and adverse conditions, tops the list, with 23% of its fatal car crashes occurring during bad weather.
In second place is Vermont, where bad weather occurred during 21.8% of fatal accidents in the state. That's followed by Washington in third place with 19.6%, Maine in fourth with 17.2%, and Michigan taking fifth place with 16.9%.
In fifth is Michigan. Bad weather was reported at the time of 16.9% of fatal accidents in the state, negatively impacting visibility and the control drivers have over their vehicles.
The most dangerous states for drivers in fall, along with the percentage of fatal crashes occurring during bad weather (2018-2022):
1. Alaska -- 23.0%
2. Vermont -- 21.8%
3. Washington -- 19.6%
4. Maine -- 17.2%
5. Michigan -- 16.9%
6. West Virginia -- 16.0%
7. Wyoming -- 15.4%
8. Minnesota -- 15.3%
9. Oregon -- 14.7%
10. Hawaii -- 13.6%
Of course, fall weather has far less of an impact in other locations. The analysis found the number one safest state for fall driving is sunny Arizona, where only 1.8% of fatal crashes occurred during bad weather. That's followed by Nevada in second place with 2.2%, California and Colorado tied for third place with 4%, and New Mexico rounding out the top five at 4.7%.
The safest states in fall, where weather has very little impact on drivers:
1. Arizona -- 1.8%
2. Nevada -- 2.2%
3. California -- 4.0%
4. Colorado -- 4.0%
5. New Mexico - 4.7%
6. Delaware --5.1%
7. Oklahoma -- 6.8%
8. Florida -- 7.3%
9. Louisiana -- 7.3%
10. Utah -- 7.6%
The study also revealed which deadliest days - where poor weather affects drivers - are still to come this fall.
November 11th is officially the most dangerous day to drive in fall due to poor weather conditions. Drivers ought to take extra care, as 119 fatal crashes occurred on this date between 2018 and 2022 – 133% higher than the average rate on a fall day (51).
The following day, November 12th, lands in second place, responsible for 106 fatal crashes during poor weather conditions over the four-year period. This is more than double the average number of crashes for a day in fall (108% higher).
In third place is October 30th with 104 fatal crashes during bad weather. Rounding out the top five is October 26th with 96 fatal accidents and November 15th with 94 fatal crashes, which is 84% higher than the average rate.
That doesn't mean winter isn't dangerous: 23% of drivers live in states where winter is worst for accidents, according to Carfax data. Those states are California, Florida, New Jersey, Louisiana and Vermont, and they have a combined 54 million drivers.
A few states stand out because they don't follow either patterns: For drivers in Nebraska and Oklahoma, spring is the most dangerous season, and New Mexico drivers have the most accidents in summer, according to Carfax.