Ticks are small arachnids often found in outdoor environments, raising concerns about bites and disease transmission. While hot weather might seem to eliminate them, ticks possess adaptations allowing them to persist even as temperatures rise.
How Ticks Endure High Temperatures
Ticks exhibit resilience to fluctuating temperatures, but humidity plays a more significant role in their survival than heat alone. They are highly susceptible to dehydration; prolonged exposure to hot, dry conditions can be lethal. For instance, blacklegged ticks die from dehydration when exposed to high temperatures and low humidity. Temperatures around 35°C (95°F) and above, especially with low humidity, cause rapid dehydration.
Adult and nymphal ticks survive extreme heat in their natural environments, often perishing from energy depletion rather than direct temperature effects. Larval ticks are more vulnerable, with survival times almost halved in frequent hot, dry weather. Studies show that at high humidity, most ticks survive 90s (Fahrenheit) for four days or more, but with mid-range humidity, less than a third survive that long. Ticks require humidity levels between 80% and 90% to prevent desiccation.
Where Ticks Seek Shelter in Hot Weather
Instead of succumbing to heat, ticks employ behavioral strategies to find more hospitable microclimates. They seek refuge in shaded, moist areas like dense vegetation, leaf litter, and underbrush. This behavior explains why southern blacklegged ticks are often found hidden under leaf litter, helping them conserve moisture.
Their activity patterns shift during hot periods; ticks become more active during cooler parts of the day, like mornings or evenings, or after rainfall, when humidity is higher. Ticks are commonly found in wooded areas, grassy fields, and gardens, thriving in warm, humid environments with abundant animal hosts. Staying on marked trails and avoiding overgrown areas can reduce encounters with ticks seeking these sheltered spots.
Protecting Yourself from Ticks in Warm Climates
Despite the heat, ticks remain a concern, especially during their peak activity from spring through late fall, including summer. Measures can help reduce the risk of tick bites. Wearing long sleeves and pants creates a physical barrier, and light-colored clothing makes ticks easier to spot. Tucking pant legs into socks prevents ticks from crawling up your legs.
Using EPA-approved insect repellents on exposed skin is an effective preventive step. Repellents containing DEET, picaridin, or Oil of Lemon Eucalyptus (OLE) are recommended. Permethrin-treated clothing offers additional protection by repelling or killing ticks on contact.
After spending time outdoors, perform a thorough tick check on your body, including hard-to-see areas like behind the knees, under the arms, around the waist, and in the hairline. Showering within two hours of coming indoors helps wash off any unattached ticks. Placing outdoor clothing in a dryer on high heat for at least 10 minutes effectively kills any ticks on fabric.