FPUS43 KLMK 121945 City Forecast for Lexington, KY Issued Sunday afternoon - Jul 12, 2015 .Sunday night... Low 73, 40% chance of precipitation. .Monday... Thunderstorm, high 88, 60% chance of precipitation. .Monday night... Low 71, 60% chance of precipitation. .Tuesday... Thunderstorm, high 87. .Tuesday night... Low 69.