Weather for Mauna Loa Trail, HI - Mauna Loa Trail, HI Weather, Current Weather in Mauna Loa Trail, HI. Local weather report for Mauna Loa Trail, HI, Local Mauna Loa Trail, HI weather. Forecast for Mauna Loa Trail, Hawaii, Mauna Loa Trail, HI weather forecast. Find your local Mauna Loa Trail weather forecast. Mauna Loa Trail, HI weather conditions.