How to stay safe in a storm

Getting caught out in a thunderstorm can be scary, especially if you’re on foot and not near any kind of shelter. You don’t have to be standing under a darkened sky to be at risk either, as lightning can strike well away from the centre of a storm, even 10 or 15 kilometres away. If you can hear thunder, you’re close enough to be in danger. A simple way to judge how near it is? Count the seconds between the flash and the thunderclap and divide that by three and you’ve got a rough idea of how many kilometres away it is. It’s called the 30/30 rule:

• Count the time between a lightning flash and the sound of thunder. Light travels much faster than sound, so the delay gives an estimate of distance.
• Count the seconds between seeing the lightning and hearing the thunder.
• Divide the number of seconds by 3 to get the approximate distance in kilometres.
• If the time between the flash and the thunder is less than 30 seconds, the lightning is within 10 km, and you are in the strike zone. Seek shelter immediately.
• If possible, do not resume outdoor activity until 30 minutes after the last thunderclap. This is the second half of the 30/30 rule.

Less than 30 seconds? Time to take it seriously and move immediately. That gap between flash and bang gives you a window to find safety before the storm is upon you.

A few years ago, I was guiding a Coast to Coast group across the North York Moors, on my favourite section between the Lion Inn at Blakey Ridge and Egton Bridge. The countryside is wide open and completely flat with no cover, and we were the tallest points on the landscape. No trees, buildings, there was nothing. The weather had been fabulous all morning, but within minutes a massive dry thunderstorm rolled in without warning. We were still about an hour’s walk from the nearest town and I knew there was no shelter ahead. I did briefly consider returning to a stone cottage we’d passed earlier, but iI was pretty sure it was locked. I made the call to have everyone drop their poles (well away from themselves) and crouch in a shallow channel that ran alongside the path. It wasn’t much, but it gave us a slightly lower profile. Thankfully, there was no rain, so we weren’t in danger of water filling up the channel. We waited it out, very tense but thankfully unharmed. It was a very quick walk into town from there!

That moment really brought home how quickly things can change and how important it is to understand what to do in a storm, especially when you’re hiking or guiding in exposed terrain.

Of course, the best way to stay safe in a thunderstorm is to not be caught in one in the first place. If the forecast mentions thunderstorms, especially if you’re in hilly, alpine, or wide open areas, it’s worth thinking twice about your plans. Weather can shift fast, and storms tend to roll in quicker than you think. Always check the local forecast before heading out. If you’re hiking somewhere unfamiliar, use a trusted local source or check the forecast through our app. Remember, conditions can change even within a few hours, so keep an eye on updates during your hike. Planning your walk to avoid a storm altogether is the simplest way to stay safe.

If you do find yourself caught in a storm and there’s no solid shelter nearby, the aim is to reduce your risk as much as possible, so you’ll need to act quickly. Your priorities are:

1. Get to the lowest safe place possible, as lightning tends to strike the highest point in an area.
2. Avoid open areas like ridgelines, hilltops, and flat plains where you might be the tallest object.
3. Avoid sheltering under trees. While it may seem safer than being out in the open, trees can act as lightning rods, and electricity can jump or travel through root systems, increasing your risk of injury.
4. Don’t shelter in small structures like sheds, picnic shelters, or bus stops. These do not provide adequate protection and may be worse than staying out in the open.

A solid building is your best bet; however, if you’re out in the open and can’t find shelter, you’ll need to make yourself as small a target as possible. That means crouching low on the balls of your feet, feet together, head down, hands over your ears. Don’t lie flat as that increases the surface area for electricity to travel through and can make injuries worse. If you’re with others, spread out a bit with five metres between each person as a good buffer to reduce the risk of multiple injuries from a single strike.

Avoid using metal walking poles during storms, and stay away from fences, railings, and anything else that can conduct electricity. Water is another danger. Being near lakes, rivers and even puddles can put you at risk if lightning hits nearby. Standing in or near water increases your chance of injury because water is a good conductor of electricity. And although your phone might be your lifeline, limit its use during a storm unless you absolutely need it. Prioritise shelter and safety over phone use. Using electronic devices outside can sometimes increase your risk.

If you’re doing longer walks, or heading into remote terrain where shelter might not be an option, consider carrying an emergency shelter. That might sound like overkill for a daypack, but there are good lightweight options out there, including bivvy bags, space blankets, or even a group storm shelter that packs down to the size of a small loaf of bread. Emergency bivvies usually weigh about 100–200 grams, are windproof, enclosed, and reflective to keep you warm and dry. Space blankets are lighter again but more basic and less durable. Group shelters sit over two or more people and provide enough protection to stay warm and wait out the worst of the weather. They won’t protect you from a direct lightning strike, but they’ll help you stay dry and warm, which matters a lot if the temperature drops or if you get pinned down by bad weather. Being wet and cold can quickly lead to hypothermia, even in milder conditions, so having something to shelter under is more important than it might seem at first.

If someone near you does get struck by lightning, the most important thing is to act quickly. It’s completely safe to touch them as they don’t carry any electrical charge. Your first priority is to get help. If they’re not breathing, start CPR if you know how. Lightning injuries can look strange, including burns, unconsciousness, hearing or sight loss, but people do survive, and early help makes a huge difference. It’s worth carrying a basic first aid kit and having some knowledge of emergency response, especially if you’re going to remote areas where medical help might take time to arrive.

After a storm passes, make sure to give it time. Lightning often trails behind the main storm cell, so wait at least 30 minutes after the last thunderclap before you head off again. Watch your footing too as storms often leave behind fallen branches, flash flooding, and very slippery trails. Muddy or washed-out paths can be just as dangerous as the storm itself, so take care when moving on.

All up, lightning is dangerous, but if you’re paying attention to the weather, thinking clearly, and carrying a few smart bits of gear, the risk can be managed. Most of it comes down to preparation and knowing when to stop. The sky might look clear when you set off but if it changes dramatically, you’ll be glad you took the time to plan for it. Being cautious doesn’t mean you won’t enjoy your trip, it just means you’ll get to enjoy many more to come.

Read more about how to stay safe on the trails and mitigate risks in our Travel and Hiking Safety section of our website.