The RAC Winter Contest is December 18th 0000z to 2359Z. Both CW and SSB modes and the exchange is RS(T) plus province for VE stations, RS(T) plus serial number for everyone else. This is always a low key, friendly event – especially on SSB QSOs. Full rules here.
The Stew Perry Topband Challenge is a 160M CW contest, running from 1500Z Dec 18th to 1500Z Dec 19th. The exchange is your grid square (no RST) and the scoring is very different and fun. The longer the distance between the two stations, the more points a QSO is worth. When the logs are scored, QSOs with QRP stations are worth more than QSOs with 100W stations which are worth more than QSOs with stations running more than 100W. Full rules here.
The ARRL Rookie Roundup is a short North America CW contests that goes from 1800z December 19th to 2359 December 19th, aimed at getting new CW ops a taste of contesting. Exchange is name, last two digits of year first licensed and state/province. Not a lot of activity in this one, but I tried to get on and work a few of the stations calling CQ. Full rules here.
If you are going to make it an all radio weekend, there is also the Croatian CW Contest and the OK RTTY Contest this weekend!