The weather in Lahaina is great all year-round, and the average temperature is in the high-70s, low-80s range. There’s also much less rain than other areas of Maui, and the trade winds usually provide a decent breeze. Hawaii doesn’t have too many hurricanes, but the official hurricane season lasts from June to November. Tsunamis are rare as well, but there are sirens that go off if a tsunami is heading toward the island, and they’re also used to warn of an impending hurricane or tidal wave.

The best time to visit Lahaina is probably between January and April, when the humpback whales migrate from Alaska. This also tends to be the busiest season, though, so people who don't like crowds, or those who aren’t all that excited about whale-watching,  might be better off visiting another time of year. Everything tends to be more expensive during the busiest part of tourist season, and hotel rooms can be hard to find. Plus, the use of certain watercraft, like jet skis and speed boats are not allowed in the water while the whales are there. So if you plan on enjoying some water sports while you’re in Lahaina, the best time to go would be May to November, when the whales are safely out of the way.

The quietest time to go to Maui is right after Thanksgiving and until the Saturday before Christmas. You will also find Maui less crowded and quiet right after Labor Day as most people return to mainland with kids starting school. But the snowbirds ( East Coast mainlanders) begin to arrive by October and some staying until spring.

The weather pattern changes every couple of miles.  Example:  Lahaina is hot and still.  There is a wind line at the North edge of Lahaina which makes Kaanapali cooler and breezier.  You get gusty wind below the West Maui airport.  You get a ton more rainfall further north in Kapalua area with huge wind  and cooler yet.  Kihei and Wailea are hot, dry and have some wind.  Maalaea area is sunny and windy in the afternoon.   Hana is cool and is a rain forest.

You can find accomodations in Lahaina area on ebay, craigslist and VRBO websites.  Many timeshare owners that are not able to trade dates advertise their timeshare units super cheap trying to recoup some income from their "Interval ownership".  In downtown Lahaina there is the oceanfront condo Lahaina Shores which is next door to shops and restaurants.    Not on a beach would be the Pioneer Inn, Plantation Inn, Lahaina Hotel and Lahaina Roads.