Why running in rain could leave you more wet, according to science

Getting caught in the rain and making a mad dash for shelter might seem like the best strategy to avoid getting drenched, but is it really effective?

That’s the question that ignited a spirited debate on Capital FM, rapidly spilling over onto TikTok and fascinating users.

In a baffling clip captioned: “Why you should never run in the rain” and “mind is blown”, broadcaster Siân Welby explained: “The science of avoiding rain.

“If you run from the house to the car, scientists say you will get more wet than if you did a sort of, like in horror films, like a serial killer walk. Just a really slow walk.”

Siân’s co-host Chris Stark, although having “heard this before”, voiced his doubt: “I don’t believe you.”

But Siân had an explanation at hand: “It’s about surface area, Chris. Because apparently, in theory, if you’re walking it’s going to hit the top of your head and maybe the back. But if you run you’re going to get smashed in the face with the rain as well. It’s going to hit the front, so you’ll get more wet all over.”

This dialogue piqued the interest of their audience, prompting responses such as “Wow,” and another listener remarked: “Running also causes the water to forceably hit you. It hits you harder.”

MythBusters previously explored this very conundrum in 2003, finding that factors such as wind velocity, covered distance, and the individual’s pace intricately influence how soaked you’ll end up.

The longstanding debate on whether to walk or run in the rain was apparently settled by an experiment that used sprinklers, concluding definitively: “It’s better to walk than run and it was very clear.”

However, when real rain was used in subsequent experiments years later, a surprising turnaround occurred; running actually left participants drier than walking. And it turns out it isn’t as easy as previously thought.

Physicist Franco Bocci brought a different angle in 2012, arguing in the European Journal of Physics that previous studies had overlooked crucial variables such as a person’s height-to-width ratio and the size of raindrops.

His research hinted the best strategy might change depending on individual body shapes, with some benefiting from an optimal speed and others better off sprinting.

Despite these complexities, his conclusion, shared with BBC News, said: “Let’s say that in general, the best thing is to run, as fast as you can – not always, but in general. If you’re really thin, it’s more probable that there will be an optimal speed. Otherwise, it’s better to run fast.”