Snow fell over Glanford Park overnight, but the temperature did not drop as far as predicted - there was a low of -2c - and the club said the pitch is playable. The snow on top of the covers helped insulate the pitch.
Three third round games were postponed by 1pm: Bristol City v Cardiff City, Brentford v Doncaster Rovers and Accrington Stanley v Gillingham.
The League One games between Leyton Orient and Yeovil Town and Walsall v Charlton were postponed, as were four League Two ties.