While locals might have their superstitions and provide you with plenty of unsolicited warnings about going in the water, the bottom line is, the water quality after rainfall all depends on your city's #drainage and #gutter systems.
Here in Los Angeles, it hardly rains. Maybe we will get a few heavy #rainstorms a year. Now, Los Angeles wasn't built for heavy rainfall, so when it really starts to pour all of the trash from the streets, oils from the roads and parking lots, and even some sewage will overflow and run downstream like a river into our #ocean.
While it's easy to see garbage and plastic floating around out there and the water may have a deep tinted color to it, what you can't see it the elevated bacteria levels that are present. This is what can make you sick. San Diego has a similar problem. So much pollution is dumped into the beaches of #Tijuana, #Mexico that it will wash ashore on the US side. If you swim or surf in this, exposing the water to your eyes, ears, and mouth... You've got a pretty strong chance of getting sick.
The good news is, not all cities are like this. When I lived in Sydney, Australia, because the city had good drainage systems in place, you could surf all through a good rainstorm.
So how can you tell if the water is clean? Some cities test their #water daily. Los Angeles county tests its water four times a day and posts the data live on the county's website. Check your city's website for more information on how frequently the water is #tested.
And lastly, how long should you wait after it rains to go surfing? Once the rain has officially stopped, you should wait for at least two full tide changes. This will dilute the water, sucking the bad water out into the ocean and washing in fresher water.