If you ever find yourself on a plane during sunset in the summer, chances are you won’t find any meteorologists on board with you.

That’s because meteorologists are privy to some key information from the weather gods: summer afternoons and evenings are prone to weather delays. 

According to NASA, thunderstorms are most likely to occur at the warmest, most humid part of the day, which is usually the afternoon or evening. And anyone who has ever experienced a weather-related flight delay knows that thunderstorms are often the culprit.

One meteorologist in particular took to TikTok to prove this theory. Chris Bianchi, a Colorado-based meteorologist with 9News, posted a video of himself at LaGuardia airport during a three-hour flight delay. Captioning the video “Why you should NEVER book a night flight during the summer (and what to do if you’re an idiot like me and end up doing it anyway),” Bianchi blames himself for breaking “the one rule” of never booking an afternoon or night flight during the summertime months in the United States.

“I’m a meteorologist, I should know better,” he says. “Chances of there being a thunderstorm somewhere in the United States in the afternoon or the evening are pretty high during the summertime months, during May, June, July, August, September. If you get a thunderstorm in the wrong place and it impacts your flight, you could be completely screwed.”

Bianchi also notes that a thunderstorm doesn’t necessarily have to occur in the destination you’re flying out of or into to experience a delay.

“If there’s a thunderstorm in Chicago and you’re flying from New York to Miami, that flight that you’re taking from New York to Miami might be coming from Chicago. So you should not book a flight during the summertime months [at night] because there’s a pretty good chance you’ll have a delay as a result of a backlog of those flights clogging up,” he says.

Garnering over 300 comments, Bianchi’s video prompted many people, including flight attendants, to chime in. One user named @beach_escape wrote: “As a former flight attendant I always tell people to sacrifice wake up and take the first flight out, always. Weather mechanics get worse in the afternoon and flight delays cause a domino effect.” Another former flight attendant, @danielle81886, added: “That rule is 100% correct, coming from an ex-flight attendant. If my schedule had a late flight, I knew I was in for hell.”

Bianchi suggests downloading the apps FlightAware and Flightradar24 to track inbound flights, and to also book a backup refundable flight, if possible, “if you notice that things are starting to get screwy with weather where you’re flying to or from.”

But if you absolutely must fly at night during the summer months, Bianchi says to be prepared to “end up like me, some dude doing a TikTok at a deserted Terminal B of LaGuardia airport at 1:45 in the morning, waiting patiently for my 4 a.m. flight back home to Denver. Good luck, everyone!”