What's too warm for trout?

[Airdog]

The other day I was on the Housatonic and had a blast with rising fish and dry flies, but was feeling a bit guilty - was the water too warm for the healthy catch and release of trout? I gave the fish plenty of time to recover before letting them go, and they seemed plenty active on the water, but... What's the rule of thumb?

[The Fisherman]

This from the TU website:

Just like humans, trout get physically drained when living conditions are too hot...In the summer months, increasing water temperatures can be dangerous to trout:

Stressed conditions. In temperatures above 72°F, trout become overly stressed and cannot function normally.
Fish-kills. When temperatures exceed 77-78°F, mass fish-kills occur. When the trout cannot find refuge from exceedingly hot water, they simply cannot survive.

[Jon]

A good time to fish the various tail-water fisheries around. Much more pleasant to fish anyway, for both fish and angler. I'm giving my brookies the month off [which is a pity because I've just been presented with a lovely custom 7' rod for my birthday! Roll on Fall].

K

[The Patriot]

Dennis at Catskill Flies in Roscoe discourages people from fishing the Beaverkill and Willowemoc if the water temp is above 70 degrees. He also strongly suggests using a stream thermometer to check before you wet a line. You can sometimes fish safely very, very early in the morning, or late, late in the evening.... but again, only after checking the water temps. Given the choice between morning and evening, I would think the morning water temps would be better than the evening, since in the evening, the sun has been beating on the water all day long, and it takes time for the water to cool off...... in the morning, the sun has been off the water all day, so it has had ample time to cool off, and conversely it will take a little while for the sun to heat it up again.

My 2 cents.

Jim