WeatherWeather Blog


An unusual weather impact

How does weather impact...your toilet?
Posted at 5:13 PM, Sep 08, 2021

I’d like to preface this weather blog with a simple fact: I am not a plumber. That will make more sense in just a bit, I promise. The next thing you need to know is that Mark, Chris, Caitlin and I (Audra) had a “weather dinner” the other night and this topic came up and Mark & Chris looked at Caitlin & I like we both suddenly had 3 heads. So, what the heck am I talking about? Well, it might be something you’ve noticed before (like Caitlin and I) or maybe you’ve NEVER noticed it (like Mark and Chris) …

On a windy/stormy day, the water in your toilet bowl can slosh around and/or look significantly lower than usual.

Yes, this weather blog post is going to tackle the impacts of weather on your toilet water. I joked I was going to do this weather blog, but then thought, why not? We wanted to know if others had noticed this, too.

A few base facts... while your pipes, of course, are underground, most plumbing systems also have a pipe that leads up to the roof to outside for, well, ventilation purposes. The other thing to know, is that our weather is always trying to achieve balance. So, an area of high pressure moves towards the area of low pressure in an attempt to balance it all out and this in turn creates wind. (Spoiler alert, the atmosphere never actually becomes balanced.)

Image of plumbing vent on roof.

As the wind gusts around and near that vent on a windy day, it lowers the pressure within the vent which acts as suction throughout the plumbing system to pull the water from the bowl back into the pipe. In a technical explanation, this is Bernoulli’s principle in action, which states “as the speed of a moving fluid increases the pressure within the fluid decreases.” The suction strength increases and decreases as the wind gusts and calms, leading to the water movement within the bowl.

Diagram of plumbing and roof vent.

So, now it’s time for you to let us know: Have you ever noticed this phenomenon in your own house or apartment? If you haven’t, keep an eye out for it on the next windy/stormy day!