Your stream thermometer can tell you the temprature of the water at the surface and a short distance down but it wouldn't be an awful lot of help in locating cold water refuges. IMHO, a reading of 70 degrees at the surface doesn't mean that the fish are stressed...they may be enjoying life deeper down or over seeps where temperatures are more to their liking.

Don't get me wrong, I'm in favor of everyone knocking the fishing off when surface temperatures reach around 70 degrees, or a little lower. The point I'm trying to get across is that the fish find cooler spots where they gather...usually becoming very easy to catch in the evening through morning hours. They're pretty hungry since they don't find much to eat during the day. When hooked, they come out of the cool water and have to duke it out in the warm water where they may not survive in extreme cases. Rapid changes in temperature are tough on the fish...ask anyone who has stocked trout. When the difference between the stocking tank and the stream temperature reaches about 10 degrees the stocking can be marginalized. I have measured vertical temperature gradients in the stream of thirty degrees in a little over 3 feet. Thats gotta give them a tough time.

I'm going to try to get NOAA to install a remote reading temperature sensor on "our" river. (some other rivers have them) Then we can get temps before we drive 50 miles only to find out its too darn warm. I suspect that they will plead poverty which is SOP for them but maybe we can find some club money to help them out!

Ol' Bill