From the weather service:

BELOW FREEZING TEMPERATURES EXPECTED SUNDAY NIGHT... .A COLD FRONT WILL MOVE THROUGH THE REGION LATE TONIGHT THROUGH SUNDAY MORNING. BEHIND IT...CANADIAN HIGH PRESSURE WILL BUILD EAST BRINGING WITH IT SOME OF THE COLDEST TEMPERATURES OF THE SEASON TO THE REGION. THE COMBINATION OF CLEARING SKIES...LIGHT WINDS AND A COLD AIRMASS WILL RESULT IN SUB-FREEZING TEMPERATURES LATE SUNDAY NIGHT THROUGH MONDAY MORNING. ...FREEZE WATCH IN EFFECT FROM LATE SUNDAY NIGHT THROUGH MONDAY MORNING... THE NATIONAL WEATHER SERVICE IN UPTON HAS ISSUED A FREEZE WATCH... WHICH IS IN EFFECT FROM LATE SUNDAY NIGHT THROUGH MONDAY MORNING. OVERNIGHT LOWS SUNDAY NIGHT THROUGH MONDAY MORNING ARE EXPECTED TO FALL INTO THE UPPER 20S TO AROUND 30.

Instructions: A FREEZE WATCH MEANS BELOW FREEZING TEMPERATURES ARE POSSIBLE. THESE CONDITIONS COULD KILL CROPS AND OTHER SENSITIVE VEGETATION.