Official statement from EFL: "The decision to postpone this afternoon’s fixture between @dcfcofficial and @CardiffCityFC was made first thing this morning following discussions between Derby County, Derbyshire Police and the local Safety Advisory Group (SAG).
"It was taken in the interests of spectator safety following heavy overnight snow falling in the Derby area which had built up on the roads surrounding the stadium.
"Cardiff City were informed of the decision and the reasons behind it as soon as it was reached."
https://twitter.com/EFL/status/975380525518151680