We are traveling next week to SF for 5 days. We're in Michigan, where it's been in the 70's but it's typically around 90 right now. Weather.com says that it's been in the high 50's, low 60's in SF lately? That seems so weird to me, is that typical for this time of year? I've been to SF 3x but I seem to remember it being warmer around this time of year. Should I pack hoodies/long t-shirts? Thanks!