This jacket looks just right for spring running outdoors in LA! The fabric is nice and thick, but it also has "built-in air conditioning" mesh inserts. It has a back pocket w/zipper for keys & cash, which I like, in terms of functionality, but if you put stuff back there you have to be very aware of who's behind you, as thieves have caught on to this design feature as well. Trust me, I had some random dude "rub" my back just as I was about to cross the street... and I didn't even have a back zipper pocket! So traumatic... until I realized I was about a foot taller than him. He ran off before I realized what he was doing. Still, it was daytime, in a very busy area. So be careful, especially if you wear headphones when you workout. There's my random fitness clothes safety tip for the day.