Our coldest month is January with an average high of 61 and low of 43. Of course it can be a lot warmer or a lot colder. Larger torts are pretty cold tolerant. Well, if they have access to heat to warm up, they can venture out into cooler air to graze for a bit as their mass helps them hold on to the heat a bit longer than a smaller reptile.Yeah I do recall a particularly brutal cold snap one year down there but I thought that it was more of a fluke than a regular occurrence.