The best time for scuba diving conditions on Maui is all year round.
Dive conditions on Maui can be affected by the surf, temperature, extensive rain downpours. The rainy season is February through March. But does not typically affect the ocean conditions unless it rains heavy for a full day straight or so.
Certain dive locations get a direct impact while others are unaffected. The water will turn brown from the soil runoff from the mountains.
As the current changes it can bring the dirty water along the shore. But this is usually short lived and then cleans up very fast.
The best time of year for dive conditions on Maui’s south side Kihei, Wailea & Makena
Dive conditions can be compromised due to the surf more often in the summer. This is due to the surf coming in from the southern hemisphere.
From May through September the southern hemisphere is having its winter, therefore the storms cause surf to come up north to the Hawaiian Islands.
The best time for diving on Maui’s West Side Lahaina and Kaanapali
Scuba diving conditions in Lahaina Maui are much more stable. We do get the surf coming in from the north during the winter from storms in the northern hemisphere.
But most of the time surf is blocked by the island of Molokai. If surf is high north of Kaanapali, we can also go diving south of Black Rock point. The surf gets blocked south of their many of the times.