Why Missouri’s weather has led to a large surge in the presence of ticks
If you've spent any time outdoors in Central Missouri recently, whether that be gardening or taking a walk, you've likely noticed a relentless, unwanted guest. Tick season isn't just in full swing; it is breaking records.
Recent surveillance data from the Centers for Disease Control and Prevention (CDC) reveal that weekly emergency room visits for tick bites across the Midwest have spiked to their highest levels since 2017. Right here at home, the University of Missouri Extension has issued warnings to farmers, hikers, and suburban homeowners alike: the tick population is booming.
But this isn't just a streak of bad luck. Looking at the climatological and meteorological data, Mid-Missouri's recent weather patterns practically engineered this exact insect explosion.
To understand this year's surge, you have to look back at our winter and early spring climatology. Ticks don't actually freeze to death during a normal Missouri winter. Instead, species like the Lone Star tick, American Dog tick, and Blacklegged tick hunker down safely beneath blankets of leaf litter and forest debris.
This biological switch flips based entirely on temperature. Ticks become fully active and begin climbing to the tops of tall grasses to latch onto passing hosts the moment temperatures consistently cross 45 degrees.
Missouri's average winter temperatures have been warmer than normal in almost every year over the past 10 years, and this winter was no different, as there was no true stretch of frigid weather. This spring kicked the trend into overdrive. February continued to stay warm in Missouri, but March ended up being the fourth-warmest on record, with almost every day observing above-average temperatures, some days even breaking high-temperature records. This unprecedented warmth broke the ticks' winter sleep months ahead of schedule, giving the population a massive head start to breed, feed, and multiply.
Temperature is only half the weather formula; the other half is moisture. A tick's number one environmental enemy is dehydration. Because they have tiny bodies, they dry out quickly and rely on high ambient humidity to survive.
Following a relatively dry winter, Central Missouri experienced a remarkably rainy March and April. The persistent dampness, paired with late-spring humidity, kept ideal areas for ticks to thrive perfectly damp. This created the perfect conditions for ticks to live on without the threat of drying out.
Due to these shifting weather patterns, there is almost a direct contribution to increased tick encounters, and because of that, a growing risk of tick-borne illnesses. While the American Dog tick can carry disease, researchers are highly focused on the aggressive Lone Star tick, which thrives in our warming climate.
Beyond traditional bacterial infections, this tick is the primary trigger for Alpha-gal syndrome, which is a life-altering condition that causes a severe, permanent allergy to red meat and dairy.
While the weather has favored the ticks, you can use the forecast to your advantage. Ticks are highly inactive during active, steady rainfall, opting to stay low in the leaf litter. However, the moment the sun breaks through, they head straight to the top of the grass.
To protect your family, pets, and livestock, there are a couple of ways to keep yourself safe. The first is keeping your lawn mowed tight, especially along wooded borders, to eliminate the tall, humid microclimates ticks love. Second, when hiking or working in brush, wear light-colored clothing to spot them easily, and tuck your pants directly into your socks.
Third, use an EPA-approved insect repellent on skin, and treat outdoor gear and boots. Finally, remember to shower within two hours of stepping inside to wash off unattached ticks and perform a thorough physical check. Ticks rarely transmit pathogens if removed within the first few hours of attachment.
