It isn't all temps. When it comes to fish there are many things that can/do/will effect the bite.
Right now I would say the water temp is only part of the equation. The full moon, and lack of cloud cover makes for some very bright nights so they feed all night. They then go deep and lay low during the day until mid-afternoon, early evening when the sun starts to drop and the surface temps cools again with more bugs also falling into the water that get to cold midflight to reach their destination. Along with those things add in the barometric pressure, water clarity, other food sources ie: nymphs, minnows, fry, etc... ok now I'm rambling. I think you get the idea.
Cuyamaca is fishable year round for trout because the water temps stay cool. I have had incredible mid-summer fishing for trout there. The temps can get to low as well which will slow the bite considerably. You may have to fish in shallower water, or deeper water, and present lures much slower to get bit when that happens. You have to be able to adapt, and be willing to try different things to get bit consistently throughout the same day as conditions change.
My point is I don't believe any one thing effects the bite so much as a combination of several. If you limit yourself to thinking one factor determines your success or lack thereof you may stay in bed one morning and hear from you Bro that it was on fire that morning and you missed the best bite of the season just because there was a full moon the night before so you decided to sleep in for the afternoon bite that never happened for you because between the morning, and afternoon a low pressure front moved in, and the bite shut down completely leaving you disappointed and unfulfilled.
In summary I would recommend that you just go fish, from sun up to sun down every chance you get so you can maximize your chances of being there whenever it is the fish decide to cooperate, and jump on the end of your line. Good luck...that is all...for now.
Oh...nice fish Keith. Didn't mean to jack your thread.