Patagonia has a bold series of claims for this lightweight and versatile mountain jacket.

At 354g (w: 294g), it meets the lightweight test for me as well as ticking a lot of other boxes that outdoor users look for in a jacket:  breathability, full-time use when out, warm when wet and comfort when in active use.

It’s quite a wish-list and after having worn the Nano Air, which is filled with 60g of a synthetic insulation called FullRange, on numerous cycling trips on cold winter days, I then took it on a cold pre-dawn trip to a hidden valley near Porters Pass. This involved an off-track hike and climb, through river bed, scrub and gorge, and finally a steep rocky climb up a rib to the tops. I found the jacket worked exceptionally well and is as Patagonia claims: very ‘athletic’ meaning the stretch fit works well when climbing steep terrain and doesn’t have you wishing you had taken it off because it was restricting movement or riding up your back. I also kept it on the entire time out, both up and down the ridge, and was surprised at how dry it was when I eventually took it off at the end of the tramp, demonstrating it’s ability to transfer sweat and moisture.

Once I stopped at the top of the ridge for lunch I did feel compelled to put on my hardshell to cut the bitingly cold sou’wester.  

The Nano Air’s lightweight construction and low volume make it especially attractive as a mountain jacket. It even handled the matagouri well.

The negatives are hard to find. I think a higher collar would be good, just for that extra snug fit when resting, and it is a little more bulky than a down jacket and the pockets, there are three, are just a tad small.