Lightning can strike year-round, but spring and summer are peak seasons for electrical storms. Although your risk of being struck is low, it is something to take seriously. The National Weather Service (NWS) reports an average of 55 human deaths per year from lightning, but hundreds more are permanently injured, with neural and physical issues including attention deficits and memory loss, sleep disorders, dizziness, muscle spasms, numbness and chronic pain.
Check the forecast before heading out to ride or work outside, especially if you'll be far from shelter, and reschedule your plans for another day if storms are predicted.
If an unexpected storm approaches while you're outside, head for shelter as soon as you notice the sky darken, see lightning or hear thunder, even if it's distant. Lightning can strike as far as six to 10 miles away from the base of the storm cloud. The best shelters are inside a building or an enclosed, hard-topped vehicle. The NWS defines a safe building as one that has four walls and a floor. Remember that electricity can radiate outward through the ground near a strike, so a dirt-floored shed or riding arena may not protect you.
If you're out on horseback and can't get to a barn, move down from high ground. Steer clear of tall, isolated trees and take shelter if you can among a stand of smaller trees that are roughly similar in height. Stay well away from metal fences, open water or utility poles, all of which tend to attract lightning and can carry the force of a strike over long distances.
If you're with a group of riders, spread out away from each other to limit the risk of everyone being injured at once. If your horse becomes unmanageable and dangerous because of the storm, let him go and seek shelter on foot. Do not lie or crouch on the ground, however; that may increase your risk of injury from dangerous ground currents.
The NWS recommends remaining in your shelter for at least 30 minutes after the last sound of thunder.