Errrm nope!
Been caught out few times over the decades.
Personally if there is a risk I would cover anyway, at least you will have a crop.
We have several sites ranging 2c to 5c tomorrow night, will be covering the toms just in case, no point risking.
Good luck
So you have tomatoes in the ground now? Presumably under glass? Are you able to successfully get them through frosts usually then to produce well? I'm in North Yorkshire and all mine are in modules and only go out in the coldframe once the sun is on it, then they come back in for the night. I hadn't considered ever trying to get them out until the risk of frost is gone and ideally the nights are much warmer.