It's no secret that we're seeing elevated water temperatures on many of our favorite rivers this summer. We've talked about getting off the water when water temperatures hit 67ºF. But, how do you accurately measure water temperature? This certainly seems like a pretty straightforward proposition, but just in case, here is a primer for taking water temperatures in the river.
When measuring the temperature of a river, it's best to choose a piece of moving water of average depth to get an accurate, representative temperature. Don't choose the deepest, fastest moving water or the shallowest, slowest moving water as it won't give you the clearest answer on what the average water temperature is. The water will be coolest in the deepest, fastest moving section and will be hottest on the slower, moving edges.
The Green Area represents the ideal location for gathering the river's temperature. Not too deep, not too shallow. Not too fast, not too slow.
Take your Thermometer out of your bag, your pocket or waders and let it calibrate in your hand for one minute.
Hold your thermometer out of the water and let it calibrate to the ambient air temps.
Fully submerge the thermometer in the river and let it "soak" for one minute. This allows for the thermometer to get an accurate reading.
Fully submerge the thermometer for one minute.
Remember, that when the water temperature hits 67ºF, give the trout a break. When in doubt, take multiple measurements. The more measurements the better. If water temps get elevated on the water you're fishing, consider hitting up higher elevation creeks, streams, and lakes or hitting your favorite warm water haunts.