There really is a Winter Field Day, and this year, it takes place over the January 30-31 weekend, sponsored by the Winter Field Day Association (WFDA). The annual event’s stated purpose is to encourage emergency operating preparedness in the winter, but it’s also a great opportunity to operate in the great outdoors. The WFDA describes itself as a dedicated group of Amateur Radio operators who believe that getting ready for emergency communication in a winter environment is just as important as the preparations and practice that take place at ARRL Field Day each June, all while taking some additional unique operational concerns into account. The WFDA points out that disasters are unpredictable, and its goal is to help enhance operators’ skills and prepare for all environmental conditions typically found in the US and Canada throughout the entire year.
http://www.arrl.org/news/winter-field-day-set-for-january-30-31