Summer's are getting cooler and Winter's are getting warmer. Last Summer (that's Dec-Feb for us) on most days I had little problem walking around with a pair of long jeans, shoes and a t-shirt. The Winter (Jun-Aug) we are experiencing right now is the roughly the same. There have been a few cold days, but overall jeans and shirt are all you need for most of the day, maybe put on a thin jacket after dusk. Actually the other day I was walking around in the city with jeans and a shirt on and I felt like cooling down because I was getting a bit hot... and this in is the middle of Winter!
It ALWAYS fascinates me how the southern hemisphere has summer where we have winter and vise versa. I know why this happens, of course, but it's more on the personal scale. Like, having a 90 degree day in January just sounds like pee-wee's playhouse kinda talk, eh?