If the blueberries finished out back, they're definitely in trouble again down here because of last night and tonight. Not sure they did though as while all of February was warm, last year almost the entire winter was warm in comparison.
Honestly it's very aggravating. I really hope at the very least we get a normal February in 2019. After you've been warm for weeks and sudden change back to mostly being cool to cold, you're not used to it, it can cause headaches, and if you hard freeze it can mean your fruit crops are toast. I hope the quota of bad Februarys after what happened in 2015 (not for everyone, but the amount of winter storms) is up and we at LEAST have an average February.