A recent ranking by WalletHub of the 100 largest U.S. cities in 28 environmental categories has four Bay Area cities in the top 10: Fremont at number 4; Oakland, 6th, San Francisco, 8th, and San José at number 10.

Overall, San Diego was the top-ranked city as California placed 6 in the top 10.

Fremont finished first in the amount of green space, water quality, and Air Quality Index,