Most deer-vehicle collisions happen in November, which accounts for roughly 25% of all annual incidents. The single biggest factor is timing: collisions are 14 times more frequent in the two hours after sunset than in the two hours before it. If you’re driving through wooded or rural areas during fall evenings, you’re in the highest-risk window of the entire year.
November Is the Peak Month
November dominates deer-collision statistics because it overlaps with the white-tailed deer breeding season, known as the rut. During the rut, bucks actively chase does across large stretches of territory, crossing roads they’d normally avoid. Does are also on the move more than usual and more distracted. In the Northeast, peak breeding runs roughly November 6 through November 20, though the window stretches longer in southern states. October ranks as a close second in many datasets, as “pre-rut” behavior picks up in late September and intensifies through October.
A smaller, secondary spike shows up in late spring, typically May or June, though it accounts for less than 10% of yearly collisions. This coincides with fawning season, when young deer begin moving independently. Fawns are unpredictable and will bolt in any direction when startled, which makes them especially dangerous near roads.
The Most Dangerous Hours
Deer are crepuscular, meaning they’re most active around dawn and dusk. The highest collision risk falls in the evening, specifically the first two hours after sunset. A large-scale analysis of over one million deer-vehicle collisions across the United States found that the post-sunset window is dramatically more dangerous than daytime driving, largely because deer movement peaks just as visibility drops.
This pattern intensifies every fall when clocks shift back to standard time. The end of daylight saving time pushes evening rush-hour traffic from before sunset to after sunset, creating a direct overlap between peak commuter volume and peak deer activity. That single clock change causes a 16% spike in deer-vehicle collisions. Researchers have estimated that staying on daylight saving time year-round would prevent tens of thousands of collisions annually simply by keeping more evening traffic in daylight.
Full Moons Raise the Risk
Lunar cycles also play a measurable role. Deer-vehicle collisions are significantly more frequent during full moon phases compared to half or new moon periods. The likely explanation is straightforward: more ambient light at night means deer forage and move more actively after dark, increasing the chances they’ll cross a road while cars are still on it. When a full moon falls in October or November, the combination of lunar activity and rutting behavior compounds the risk.
Fog, rain, and wet roads during autumn also contribute. These conditions reduce driver visibility and reaction time, though the deer themselves are driven more by breeding behavior and daylight cycles than by weather.
Where You’re Most Likely to Hit a Deer
Geography matters almost as much as timing. The states with the highest collision odds tend to be heavily forested with large deer populations and extensive rural road networks. For the 2024-2025 period, the top five states ranked by likelihood of an animal collision claim were:
- West Virginia: 1 in 40 odds
- Montana: 1 in 53
- Wisconsin: 1 in 58
- Michigan: 1 in 61
- Pennsylvania: 1 in 62
In West Virginia, you have roughly a 2.5% chance of filing a collision claim involving an animal in any given year. That’s more than double the national average.
Deer Whistles Don’t Work
If you’ve seen the small plastic whistles sold at auto parts stores that claim to scare deer away from your vehicle, save your money. Research at the University of Georgia tested five different sound frequencies on both captive and free-ranging white-tailed deer. The deer showed no meaningful change in behavior in response to any of the sounds. Earlier studies on mule deer found the same thing. Deer simply don’t react to these tones in a way that would prevent them from stepping into the road.
What Actually Reduces Your Risk
The most effective strategy is adjusting your driving to match the known risk patterns. Slow down on rural and wooded roads between sunset and midnight from October through early December. Use high beams when there’s no oncoming traffic, and scan the road edges for eyeshine, the greenish reflection of headlights off a deer’s eyes.
If you see one deer, expect more. Deer travel in groups, and a second or third animal often follows the first across the road within seconds. Resist the urge to swerve sharply, which frequently causes worse outcomes than a direct hit. Braking firmly while staying in your lane gives you the best combination of speed reduction and vehicle control. Pay extra attention in areas posted with deer crossing signs, near streams or rivers where deer drink, and along tree lines that border open fields.