We have all heard the water temperature of tropical beaches described as “Just Like Bath Water”. But I don’t really know what that means. How hot is bath water? How hot are the beaches? How hot does the water have to be before I will swim? What places in the world have the best water temperatures for swimming? So, I decided to investigate a bit more and bought a small water thermometer a couple of years ago. I know… I am kinda weird.
Several years ago we took a family trip to San Diego during the summer. I have told the story many times about how we swam at La Jolla beach one day and then flew home to Washington State to finish our vacation at our family beach place on Stretch Island. My story is that the water in Washington was warmer than the water in Southern California. The theory is that our Stretch Island beach (with a 15 foot tide variation) has sand that heats up when the tide is out and it will warm up the water when the tide comes back in. I am not really sure if this is true because I hadn’t bought my thermometer yet. I just remember being really surprised at how cold the San Diego beach was and how Stretch Island was possibly a bit warmer.
So now I am going to track the water temperature of our travels and I thought some of you might be interested in what I have found so far. My baseline is my favorite swimming spot at Seward Park in Lake Washington. After we retired, we typically hang out here a couple of times a week during swimming season. This is not unusual among Seattleites and most people have their favorite spot on the lake. Ours is under a maple tree on the south shore of Seward Park. The temperature for us is perfect in July and August. It can be a bit chilly getting in, but it feels really good on a hot day. This week, I measured 76.5 degrees F. I feel like this is my minimum comfortable swimming temperature.
I have been measuring since September 2023 but I dropped my thermometer getting off a boat in the Galapagos in March 2024 and didn’t get a new thermometer until January of 2025. I have missed a few temperature reading opportunities but I still think what I have recorded is interesting. At least to me… Temperatures are in Fahrenheit.
I need many more data points to really understand this. I am upset that I have forgotten to check water temps in many of the places in the past year. I will keep measuring and try to update this blog post as I get more locations in the next couple of year. Let me know if you have taken some interesting water temps in different parts of the world. What places have the hottest bath water???