I actually have a lock in my bag. For got to mention that. I shnouldn't need it, though, as I can just lean my bike up against the wall next to my desk.
I don't have a spare tube. I just used my last one on my other bike. I need to pick one up at the bike shop. So, I'll have to make do with a patch kit, or swing by the shop tomorrow.
Forecast looks good 
, but that's pretty much what it'll be like all summer. I'm not worried about rain for at least 4 more months
I do need sunglasses. Unfortunately, I don't own any. I've been meaning to buy some for a while. I ride a fair amount without them anyway, though, so I should be ok.
I'm thinking about getting some pedals with clips and straps, but I know I can do the distance on platforms. I've done the ride before, just not as a two-way commute. Also, I can wear sneakers at work so I don't have to worrk about cycling in nice shoes or anything. Typical work attire for me is jeans and a t-shirt
Food is a good idea. I'll probably just buy something at the store on campus, though. (I work on a college campus) so I don't have to carry it around with me.