It has been raining all night and morning here in Kihei so was thinking for an activity doing hana highway.
Is is safe in the rain?
and is it worth it in the rain?
Thanks in advance :)
No, and no.
There will likely be some landslides and trees down as well as the day goes on.
Though the rain here isn't heavy and pounding, it has indeed rained most of the night all over Maui. We may see some very heavy rains off and on as it moves in from Moloka'i.
For an alternative, drive down to La Perouse and walk the trail there. In rainy weather it will be cooler and offer some dramatic scenery. You could also explore 'Iao Valley, but I'd do that first if you want to see it.