When do you fly fish?

[birdbeast]

Thanks for the input on my hook sourcing question.
With self isolating I have been watching a lot of You Tube videos and have found a bunch about winter fishing in Colorado, Utah and Idaho. The videos show them fishing in January, February and later.
My question is : Do the members of AO fish during the winter? If you do, what is the trigger to go out ? Do you watch weather forecasts and go when it is more mild? How do you dress? Breathable or neoprene?