Monsoon prep — June, before the first cell
Annual · typically June · weather can move it up
Why it matters
Desert rain is a different animal. your county spends most of the year bone-dry, then monsoon season drops months of water in minutes, wrapped in 60-mph outflow winds and a wall of dust. Houses here fail in ways Seattle houses never learn about: scuppers clogged with nine months of dry debris, grading baked into a ramp that aims water at the slab, and evaporative-cooler pads and AC filters packed with haboob dust.
What skipping it costs
$800–$15,000
Monsoon rain doesn't fall — it arrives sideways, two inches in an hour, onto ground that spent nine months baking into pavement. A clogged scupper turns a flat roof into a swimming pool that weighs ten pounds per square foot per inch; a washed-out grade sends that same water under your slab. The repair after one bad cell costs more than a decade of Junes spent doing this list.
Two ways to get it done
Do it yourself
You'll need: Ladder (or binoculars for the roof part), Garden trowel, Hose, Spare HVAC filter for after the first dust storm.
- Clear every roof drain. Scuppers, canales, gutters, downspouts — by hand, then run a hose through them. Water should exit fast and away from the house.
- Walk the grade. Hard-baked desert soil sheds water like concrete. Anywhere the ground slopes toward the house, cut a path away from it now — a trowel in June beats a pump in July.
- Stage for dust. Buy the spare HVAC filter now. After the first big haboob, swap it — one dust storm can load a filter like three normal months.
- The yard scan. Patio umbrellas, trampolines, shade sails — outflow winds arrive ahead of the rain with almost no warning. Everything that can fly needs a five-minute stow plan.
- Look at the washes. If your lot backs to a wash or drainage easement, make sure nothing of yours is stored in it. That's not pessimism; that's what the easement is for.
Hire it out
$150–$400National fair range — local labor moves this number.
A flat-roof monsoon check — drains flushed, ponding spots mapped, penetrations eyeballed — runs $150–$400 and is honest money if your roof is flat and older. Ask for photos of anything they want to fix.
The one rule that matters more here than anywhere: nobody who knocks on your door after a storm gets hired. Monsoon season is door-knocker season in the desert. The good roofers are booked and don't canvass; the trucks working the neighborhood the afternoon after a haboob are selling fear with a clipboard.
Ask the tech
- Are the scuppers and canales actually draining, or just clear at the mouth? Run water and show me.
- Where does this roof pond after ten minutes of hard rain, and is that spot growing?
- If you're patching, is this a coating repair or a substrate problem?
Red flags you're being upsold
- The post-haboob roof crew knocking the same afternoon dust settles — 'we were in the neighborhood and saw damage from the street.' They see a neighborhood, not damage.
- A full re-coat pitch every single year. Elastomeric coatings are a 5–10 year cycle, not an annual subscription.
- Storm-chaser hail claims in monsoon country: 'we'll handle the insurance for you' plus an assignment-of-benefits form is how you lose control of your own claim.
Second opinion time: Any flat-roof replacement quote over $8,000 that started as a 'free monsoon inspection.'
The call
DIY the walk and the clearing in June. Hire the roof-drain check if your roof is flat and you can't see the scuppers — that one's worth a real ladder and real experience.