Naturally the North American, Swiss, Scandanavian, Baltic and Russian snow and ice is an issue, but in temperate UK after all the rain, it is player avaiability that is leading to cancelled matches.
And late cancellations are getting worse and worse. It is always a bigger issue during 6 Nations (not just players but refs too who want to go to Twickenham !).
Last few weeks the late cancelled numbers or matches are up over 10% and we have had two L8 League matches canx - Old Wimbledonians and London South Africa pulled out of trips to Hampshire, plus Fawley L10 could not get a FR and this weekend a Senior Merit table 2nd XVs of L5 clubs has been cancelled.