In terms of major cities, San Francisco is among the best choices in terms of year-round weather. Snow, subzero temperatures, and associated clothing needs would definitely be much more problematic in your suggested cities.
The Bay is very kind to Homo sapiens, in terms of climate.
This is not "I've lost everything and am homeless with no way out" it's "I wanna build a startup so I'm going to go live in a van".
Landlords very often just won't take you on at all if you don't show evidence of preëxisting stability. No proof of stable income? No housing—you can even offer to pay up-front or whatever, and they just won't bother dealing with you as a special case, because why would they deal with the special case when there's a dozen other safe, predictable, normal people in line behind you?
Got an income, but can't prove it to be consistently enough? Congratulations, no housing for you. And thus begins the downward spiral.
I had to get my parents to co-sign on a lease... at 27, with a PhD, proof of employment, and "excellent" credit. It's pretty insane.
I doubt most of the folk we dealt with would have taken us on even if I had offered to pay a full year's rent up front. It's just not worth the bother when there's a dual-income, no-kids couple with good credit next in line.