It means it’s usually really hot. I can deal with that, though. The reason it really sucks is that BART is free on those days (like today!). And when BART is free you get lots of homeless people that ride it for the air conditioning. I got on a train this morning and the car I was in had at least 4 homeless people asleep/passed out in that end of the car. Luckily the next car only had one in the first half so I sat there but the smell was still pretty overwhelming. BART probably hopes that the extra people that try to take advantage of the program will start using the system more often but I can tell you with pretty much certainty that it’s not going to help matters. They need to find a way to boot non-destinational riders for riding the system and enforce them not taking up 2-4 seats while they sleep, even if the cars aren’t full.