Nothing disrupts the safety of a clay court more than frost. If heavy enough to penetrate the ground, frost will cause a “heaving” action where the nails that hold down the lines will actually lift the lines out of the court, causing obvious safety hazards.
If you plan on playing outdoors at FCC this week, please inspect your court carefully. Unfortunately, if this weather pattern continues I will have no choice but to remove the lines for the 2019 season so no one gets injured.