It's very hit or miss. Somehow both times we've been in February in the last 5 years, even though once was toward the beginning of the month and the other time was toward the end of the month, we managed to hit record low temps. While there were warmer days while we were there, it was never quite warm enough to think about swimming. I'm sure it depends on the year and the day though... I wouldn't say it's ruled out to swim by any means, but I wouldn't count on it on any specific day. And bring something warm to wear just in case!!!