As per One Piece wiki
Kenbunshoku Haki, also known as Mantra on Skypiea, is a form of Haki that allows the user to sense the presence of others, even if they are concealed from view or too far to see naturally.
This is the aura which is seen through Kenbunshoku Haki.
The user can also use this Haki to predict an opponent's moves shortly before they make them, thereby making the attack much easier to evade with enough skill. This prediction appears to the user as an image or brief "premonition" of what the opponent will do in the user's mind's eye, and the damage the user will take if the attack actually "hits". It appears that the more killing intent the enemy has, the easier they are to predict. Although, more skilled users can predict future moves whether there are ambient murderous intents or not.
Hence, Zoro detecting the change in climate can't be a consequence of his Kenbunshoku Haki, because it's inanimate and has nothing to do with a living thing. It's not possible to detect the "aura" of climate either.
Though the power allows the user to predict most attacks, it can be circumvented by various means. It cannot predict inherently random attacks; for example, Luffy managed to bypass Enel's Mantra by bouncing his fists off a nearby wall, to prevent himself and thus Enel from knowing where they would land.
As for Zoro sensing the halt of the ship in the Calm Belt, it's highly unlikely that it was his Kenbunshoku Haki as well because the Straw Hats had merely begun their journey then, and noone was aware of their Haki, or even unconsciously used it. Not to mention, the halting of their ship was not intentional (a result of the action of another living thing).
I think it's more of Zoro keeping an eye out for changes in the surroundings than it being his Haki.