Kinda surprised nobody guessed this one, so I'll give it a try.
Drought and famine have nothing compared to me,
Hurricanes wreck havoc on an extremely large scale, that can take many years to fix. Whereas drought can be fixed with a single, good rainfall, and famine can be fixed with a single, good crop yield.
Even those with iron stomachs will hurl once they see.
Large ships are made of iron, and ships are considered to have bellies.
Can you suffer to touch me, to clear me out? A date with me turns into a serious bout.
Being around during a hurricane can be disastrous, if not deadly. But those who do are "touching" the hurricane.
Yet I am present always, a natural part of life.
Hurricanes happen naturally, every year, multiple times a year.
A second part, now to come. An unlucky day, especially for some.
Hurricane Florence is going to hit land very soon. When a hurricane hits land, that would be its second part (the first being when it's on the ocean). And those in the Carolina area are going to have a very "unlucky day" when it does hit.
DECAY -- Hurricanes cause a lot of decay as they break up and wash away large things, land, trees, houses, etc.