Originally Posted by fredaevans

Darned interesting thread. Had no idea that Rainbow free spawning was so restricted in the UK. As to water temperature, their preferred range is 42 to 55 degrees. Below that number their systems tend to shut down and they go 'dour.' Above that and (frequently) the warmer water will have a reduced oxygen content.

It gets darned hot around here in Southern Oregon during the summer and we have one major river (the Klamath which flows out of SE Oregon, into California and finally into