If there’s a thunderstorm raging outside you might wonder, what happens if lightning strikes a swimming pool? Are swimmers in any danger, and could the pool itself be harmed by the strike? The science behind the answer is interesting, plus anyone who owns a swimming pool should know exactly what they’re risking during a storm.

How Lightning Effects Pool Water

Lightning tends to strike the highest point, but height isn’t the only factor in where it hits. Strikes routinely ignore tall homes and hit the relatively low surface of the nearby swimming pool. Plus, as water conducts electricity, it spreads out the impact of the strike.

This isn’t a good thing, as it will charge the water so that everyone who is in the water is shocked, even if the pool is large. Lightning also creates a lot of heat, so the water will steam and probably splash out onto your deck or home.

If you’re in electrified water, you may suffer electric shock and burns, even if lightning doesn’t hit you directly. You can die from indirect lightning strikes in pools, so you should avoid swimming during thunderstorms.

If You’re In the Pool During a Lightning Strike

While your swimming pool’s water conducts electricity, your body is actually a much better conduit. Just as lightning prefer high things, it also prefers better conduits. Therefore, the odds of you being directly struck are high, compared to the odds of the water striking just the water near you. A direct strike can cause death by stopping your heart.

Being hit by lightning will also be very painful, even if it doesn’t stop your heart. You’re likely to suffer serious burns. This is more dangerous when you’re I water as the pain and shock from the strike may make you unable to swim, even if your heart is still beating. As lightning is likely to hit nearby again, those who attempt to rescue you are also in danger.

Of course, that all only applies if you’re in an outdoor pool during a thunderstorm. Indoor swimming pools are more secure from lightning, as they are usually in grounded buildings, that can be hit by lightning without causing any harm to the occupants.

You can install a similar grounding system to an outdoor pool that can reduce the danger of lightning, but these are expensive systems.

What About the Pool Itself?

While the first priority is the safety of the people in your pool, you may also be concerned about the pool itself. A lightning strike can damage your pool’s pump, filter and heater. The strike overloads the electrical circuits and can ruin the equipment.

You can install surge protectors to prevent lightning from damaging your pool, but that’s just another cost that makes pool ownership too expensive. Instead, we recommend you swim in public indoor pools, where you’re safe and don’t have to worry about lightning even if it’s raining outside.