It's not a luck or co-incidence, of all people Zoro sensed first that their Ship isn't moving (when they entered Calm belt for the first time)

In episode 385 he sensed (along with Nami) change in climate before Serpent Currents emerged.

There are several incidences he has sensed changes in Climate and motion before all (or along with Nami, who's a navigator) in the series

Is it zoro's Kenbunshoku Haki, which was active all time? or does he have any special ability? Isn't it noteworthy? I don't see any sources highlighting this ability of his (even in Wiki)!