Police say Martha Young Williams and Jean Young Haley lost their footing in the driveway of Ms Haley's house in the town of Barrington on Friday.
They were found by a neighbour on Saturday morning and taken to hospital, where they were pronounced dead.
The siblings' family said the women had lived with charm, kindness and style.
In a statement on Monday, the relatives said the pair were an inspiration with a great passion for life.
The twins had just returned on Friday night to Ms Haley's home from dinner with their 89-year-old sister.
Investigators say Ms Williams lost her footing first and Ms Haley fell as she tried to go for help.
Barrington Police Chief John LaCross said: "Ms Williams may have fallen in the driveway walking to her car.
"Ms Haley may have tripped on a rug on the floor of the garage as she attempted to enter her house to call for assistance."
Police believe the women died of hypothermia.
Temperatures had dropped overnight to as low as 11F (-11C).
Ninety-seven-year-old twins have died in freezing temperatures after falling over outside one of their homes in the US state of Rhode Island.