Indian Summer in December?

We're having unseasonably warm weather this week, and are expecting rain.  High temperatures are expected to be in the 60's, and may hit 70 by mid-week.  The overnight lows are expected to be in the 50's.  It's feeling downright balmy!  Tomorrow I plan to remove the fabric row covers that have been protecting my fall crops from pests and severe weather in order to take full advantage of Mother Nature's sprinkler system.