Try Mount Abu ...I have been to there last year....it was hot in Ahmedabad...but it was foggy early morning...chilling at night must experience....plus it's very neat and clean pollution free...with nominal rush of tourist
Please go visit Matheran, Maharashtra. It's the most beautiful and cleanest hill station I've ever been to. They don't allow sny vehicles up there. It's pollution free. It's the most viby place. It has the beautiful sunrise and sunset points. You'll just love it there.