Rain fell from Sunday evening and through the night, resulting in organisers having to delay the scheduled start from 1100 (0900GMT) until 1200 (1000GMT) at the earliest.
Rain is forecast to keep falling throughout the day.
Two women's last-16 matches were suspended when heavy rain started to fall late Sunday.
Second seed Agnieszka Radwanska was 6-2, 3-0 up on Bulgaria's Tsvetana Pironkova and sixth seed Simona Halep of Romania was leading Australian veteran Samantha Stosur 5-3.