I figured as such, many variables and understandable that manufacturers don't want to absorb that responsibility. They know, though. Pata has a blog post up which states >"If you’re looking for a jacket for temperatures well below zero, go with a fat jacket like the Ina_down (0˚C), the Stealth Downer Jacket, Lined Canvas Hoody or Down Jacket should fit the bill for men; and for women, the Down With It Parka, Fiona Parka, or Upside of Down Jacket should keep things toasty."

So, they are kinda riding the line. I read another blog with a retailer saying how bad temp ratings would be for jackets due to variables such as humidity, level of activity, etc. All the obvious stuff. All valid. Ok, well then add a huge asterisk and do it under standardized conditions. If you can establish a temperature ratings system for sleeping bags, you can do it for the insulation used in jackets. Maybe the sleeping bag data could be transferred since something like a puffy would be used while standing around anyways.

It's harder with for example the various iterations of the nano-air jackets (I think there are 3 now). Ok, I night hike. Temps are high 40's low 50's. Must I buy each one and test? This seems like achievable data for pata if they would be willing to asterisk the hell out of it.