that's a no-brainer for me, if it's reasonably convenient for me to get my bike off the street and secured behind a locked door, then that is the obvious answer. every. single. time. it has nothing to do with weather and everything to do with keeping my bike and it's components out of the public realm so that thieves and punks can't steal or mess with it.

i have access to a secure, locked basement storage room at my office where i am allowed to store my bike during the workday. there's no elevator in the building so carrying my bike up and down the narrow and steep basement stairs everyday is a touch annoying, but it's millions of times less annoying than having my bike stolen.

however, i live in chicago where something like 8 billion bicycles are stolen every hour, so i may veer toward the paranoid end of the bike security spectrum. the reality of bike theft where you live may be different and require a different risk assessment.