Recently someone commented that the water coming out of their drip irrigation head was 130 degrees. I admit – that’s pretty hot, but there is a simple explanation for it.

Below is what I euphemistically call my “outside shower.” There is a bottle of boy wash somewhere. Just not in the picture.

It is merely a hose on a hose reel that sits in the sun until about 3 PM in the summer, and to about noon in the winter. On mild days in the winter, I can actually shower outside. On summer days, the water gets pretty hot!

One time, when I was showering off, I thought – damn, this water is very hot. It turns out that I was standing on a red ant mound. That’s another story.

Anyway, how hot does the water get? I decided to test it with an instant thermometer. You have to believe me that the first bit of water exceeded 110 degrees, but I fumbled around with my phone. Finally, I got a decent shot.

This reads 103.4 degrees. The temperature went up and down, mainly because the water in the hose that is protected from the sun is not going to be as hot as the water that is in the sun. One other factor – just having the water go through the nozzle will cool it a bit. (When you spray through a nozzle the water gets converted into tiny droplets, thus the surface area increases. Due to the increased surface area, the heat dissipates to the surrounding air molecules the water’s temperature decreases.)

So, how does that compare to the inside water? I was a bit better with my phone on this one.

I decided to take the water temperature at the kitchen sink.

Here was the result.

This is the temperature at the kitchen sink. That is almost exactly a 30-degree difference from the outside.

Now imagine that you have drip irrigation lines (usually black) stretched for 50 feet or so. The temperature of the water will probably get to 130.

So, what to do?

First, cover your lines with mulch.

Second, water at night!

There is no way municipal water will be coming out of a tap at 100 degrees or so. The lawsuits would be incredible.