Why so late in the evening...

[chucky]

I popped to a creek last night after work for a couple of hours fishing and it was completely dead until sun down. Pools where i caught dozen of brookies in the day a week ago didn't have any action what so ever, tried dries, small and bigger nymphs, mini leeches... Nothing until the sun went down.
I'm still learning so i'm curious, why such a difference? I had warmer days with more action so I don't think it's the temperature.

Any one with a theory / possible explanations?
Thanks