Will it be snowing in December in Xian?

Probably, but not sure about this Dec. According to the reocrds, it did snow lightly in Dec. in 2011 and 2012, but had no snowfall in Dec. 2013.

probably no. no snow in xian, if you are living in the city like my place in the gao xin high tech zone. the last time we saw snow there was 2012 february it did cover atleast 5 inches thick but melted the next day so its kinda dirty.
december 24, 2011 midnight of christmas but not very snowing. but the weather is always ranging from 0 to 5 from november til end of feb... hope this helps.