Entry is made by guessing the first day where the temperature is below zero degrees fahrenheit along with the hour of that day to be used for tie-breaking purposes if multiple people guess the same day. In the event that multiple people guess both the day and the hour where the temperature first drops below zero then the winner will be determined by a random drawing of all entries that had the correct day and hour. The winner will receive a $500 gift card to Lettuce Entertain You Restaurants. No purchase necessary. Only one entry per person allowed. American Weathermakers reserves the right to modify or terminate this promotion at any time. Lettuce Entertain You Enterprises is not affiliated with this contest or American Weathermakers. Entrant must be 18 years or older and reside in one of the following counties of Illinois: Cook, Lake, McHenry and Kane. Entries must be received at least one day prior to the first day of zero degree or less temperatures. Temperatures are as measured at Chicago/Waukegan Regional Airport and reported at w1.weather.gov/obhistory/KUGN.html. Contest void if no daily temperature drops below zero prior to March 31, 2018 or no entrant correctly guesses the first day after 11-1-17 where the temperature is below zero. All decisions pertaining to this contest are final and at the sole discretion of American Weathermakers. Gift card must be picked up in person during regular business hours at American Weathermakers' office in Northbrook, Illinois. Winner must present a photo ID and sign a contest release form. Participation in this contest automatically signs participants up for the American Weathermakers email list. Within 5 business days of the first day below zero, American Weathermakers will notify the winner or winners by email. The winner must respond to their notification within forty eight hours or another winner will be chosen.