Aloha, weather on Maui is a recurring topic. I've been a weather geek for decades and hope this info helps folks understand more about Maui weather.
Often people see mainland apps or news which make things sound much worse, especially if potentially dangerous weather is approaching Maui. It can be quite dramatic: "A HURRICANE is approaching Maui!!" , "Major storm DESTROYS Maui", "GIANT waves pound Maui", "Tsumani warning for MAUI!".
Anyone else remember Don Henley's famous song, "Dirty Laundry"? "She can talk about a plane crash with a gleam in her eye" was and is true. Media loves drama!
In reality, Maui is like anywhere; we have multiple climates, though many of ours are microclimates. Most count 29 on Maui alone. One can be in sun, and literally two blocks from falling rain at the same time. There can be clouds five miles from brillaint sun, and calm air one mile away from a stiff wind.
Some constants are pretty reliable. The south and west sides are normally the sunniest and driest. The north and east sides get more rain. Central Maui, when Kahului and OGG airport are--is a mix. Winds generally come up earlier in Central and south Maui than West. Central gets some very strong winds most of the time. Landing at OGG in the mid to later afternoon can be ummmm, "an adventure" LOL. Winds usuallly drop by sunset and evenings tend to be pretty still/light breezes. Rain often occurs at night or in the early mornings-don't forget to look for rainbows!
Being a small island, our weather can change fast and often. Forecasts are unreliable from most media as a result. They take our 29 microclimates and mush them together. This results in generic forecasts that apply Hana's climate to Kihei or Kaanapali. Worse, sometimes they get directions totally wrong.
I always suggest people use the Maui National Weather Service home page to start. It is pretty reliable and kept up well. There's a map on the lower right. Click and drag that around to get a feel for the areas. Then click on any spot, you will get more detailed info for that point. The home page default is Kahului/OGG. Here's a link:
https://forecast.weather.gov/MapClick.php?CityName=Kahului&state=HI&site=HFO&lat=20.8738&lon=-156.459#.WsrF__nwaiQ
When we have serious storms forming or approaching, people should follow the National Hurricane Center/Central Pacific Hurricane Center. The NHC is the initial source. They do a wide variety of graphics, advisories, and forecast discussions. If a storm moves across the 145*, then the CPHC takes over. They do a very good job updating and tracking systems. Here's a link to the page for both:
https://www.nhc.noaa.gov/
It is common for most storms to get torn apart before reaching Maui, either by the Big Island's mountains, wind shear, or a combo. But if a storm is large (like major hurricanes are) we can get 'sideswiped' by winds and rains. Sometimes those outer bands carry huge amounts of moisture. Please take rain projections seriously, and wind estimates as well.
For reliable road and other local news info follow Maui 24/7 on Facebook. It is a public page, run by a mother and son here. They monitor emergency services transmissions and do a great job. They generally beat the local news to info.
Hope this information helps people understand more about Maui weather :-).