In March it rains. It rains throughout the year in Hawaii, but March rain is unlike the scattered showers or winter storms at other times during the year. In March it rains with concerted effort over a period of days. It rains with purpose and emphasis; not passing showers, but lasting downpours, nights of thunder and days of gray. In 2006 it rained the entire month.

You can count on rain in March, and you can count on the things that come with the rain, like the morning mud smell in elementary school classrooms, where kids are still too young and too impulsive to keep from stomping through chocolatey puddles on the way to class.

There will be toadstools in the neighbor’s yard a few days after the rain. You can count on those. But not in your yard. Oh no. You’ll kick them down as soon as they raise their impudent heads above the grass. Get them quick before the dog eats them and gets sick. Get them quick before the kids see them and get silly ideas about fairies and gnomes.

If the rainstorms come with lightning, Diamond Head will go from its usual brown to a cheerful green a few days later. That’s because of the nitrates in the atmosphere. Look for it. Point that out to the kids. That’s science right there.

There are other things, too, like bath towels that won’t fully dry on the towel rack, snails that emerge to seek higher ground on sidewalks and driveways, black moths taking shelter in the eaves, the low branches of mango trees already heavy with early fruit bending all the way to the ground with the weight of all that water.

You can, of course, count on sewage and wastewater spills if the systems become overwhelmed with rainwater and surface runoff. You can count on the ocean being brown and murky in the places where a river mouth opens to the beach, and that means you can count on fish and turtles coming close to shore to feed on the vegetation that washed downstream.

Of course, that means sharks will be attracted to the fish and turtles, and so those warning signs go out, hopefully before any person has a close encounter with jaws. You can always count on some people disregarding warning signs about murky water, shark sightings or any number of hazardous conditions at the beach, on hiking trails and near storm drains. Some people think those signs are for everyone but them. You can count on rescue crews from the fire department being very busy when it rains.

But also, March rains come with the certainty of surprise, of stormy nights that lead into golden dawns, days so clear and sunny that it seems the stage was reset to another place and time. Only the high-water mark of left-behind debris along the outside of the garage is proof that, just a few hours ago, it was pouring.

Reach Lee Cataluna at 529-4315 or lcataluna@staradvertiser.com.