* WHAT...Sub-freezing temperatures as low as 31 possible. * WHERE...In Connecticut, Northern Fairfield, Northern Middlesex, Northern New Haven, and Northern New London Counties. In New Jersey, Western Passaic County. In New York, Orange and Putnam Counties. * WHEN...From late Saturday night through Sunday morning. * IMPACTS...Frost and freeze conditions could kill crops and other sensitive vegetation. Take steps now to protect tender plants from the cold.