20km each way. Some urban, some hills.
Generally I'll wear "regular" non-work clothes and generally shower & change at work.
Something like Dockers shorts down to about 35 or 40F, then add a layer of sweatpants. ... Although last February, I arrived at the office in shorts on a 25 degree day and told our new hire that if it got much colder I was going to have to start wearing long pants. (I'd removed the outer layer a mile or two before getting to work - but it was worth seeing the expression on his face!).

Shoes I can walk 3-4 miles in if I have to.

A good (Burley) rain coat if it's needed - that's my only "bike specific" thing at the moment. Well, that and a helment.

At over 100F, I really like loose fitting, light colored clothes - on or off the bike. A thin long sleeve button down in white or yellow, opened at the front and over a T-shirt I find far cooler than a jersey when the outside temperature is at those levels.

I go back and forth on the whole bike shorts thing. It's kind of a recent phenomenon. We don't need half the stuff we view as essential, I think.