According to the Member Guidebook, the average high temperature at Vero in February is 74 degrees and in March 78 degrees. The average lows are 52 and 57. Average rain is 2.9 inches in February and 3.1 inches in March which is low compared to the may through November period.
But then again, when is anything average? It seems like you either get a flood or a drought.
We have never been to Vero but we always go to WDW in February and the weather has been wonderful.
HBC