Don't quote me, but if your in the continental United States right now it'd be pretty hard to accomplish today. Cold smoking requires a few days of smoke produced below 160 degrees... It's a science thing, I know I looked into it because I LOVE SALMON!! And the equipment needed in warmer temps (like in the US in most areas in August) to cold smoke is nothing for the faint of heart...
However, you can "smoke" salmon like other smoked meats and its awesome for quite awhile in the fridge/freezer (I don't freeze anything, ever!)...
So are you really trying to cold smoke salmon (which is like a jerky like consistency) or are you trying to rock salmon like a meal?
Here, look, this is salmon smoked at 225... Whole sides... Despite the glistening, almost shellac apprearance, I could slice of a fillet (like you'd get I'm a restaurant times 1 zillion I'm flavor) or take a hunk and flake off over a salad or eat a hunk for breakfast, midday or midnight snack... Cuz that's what I do since I'm the only one that eats it in my house...
I waited for the pellicle to form, a waste of time for who I want to use salmon, it just doesn't make a difference, totally, when hit smoking (I understand its a big deal cold smoking)
this is the Salmon that achieved pellicle stage prior to smoking... In this image, the fish is done, it's lite, fleshy... It's good!