No you need at least 30 days notice to quit to terminate month to month tenancy in New York State. This question has already been answered on Avvo.com here: http://bit.ly/Z2lVZw
Now, there may be a wrinkle with this condemnation business, but I'd suspect that only a MUNICIPAL condemnation by a building inspector for an imminent threat to health or safety counts, not some decision by the landlord's insurance carrier not to insure the building, if that's what's going on.
Tell your landlord to give you a valid notice to quit. Look at the cited link above for timing (when in the month it must be done). Get a landlord/tenant lawyer. The landlord cannot evict you by self-help or lock you out. He must get a valid warrant of eviction after bringing a petition for eviction in a local court, of which you will have notice and an opportunity to appear. So, look for a new place, but relax about being kicked to the curb in three days in the middle of the winter.
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