Phoenix gets about 7.22 inches of rain a year and humidity near 19 percent in June, then monsoon haboobs in summer. Here is where that dust lands indoors and how to keep up with it.
In a wetter city, rain scrubs the air every few days. Phoenix goes weeks without it, and in late spring barely any falls at all. Dust stays aloft, drifts through door gaps and window frames, and settles as a fine gray film on every flat surface.
Then, in summer, the monsoon can roll a wall of it across the Valley in an afternoon. This guide explains the two kinds of Phoenix dust, where each one collects, and how to keep a home ahead of both.
The 1991 to 2020 normal at Sky Harbor is 7.22 inches of rain a year. May averages 0.13 inches and June just 0.02, and in June the average relative humidity can fall to about 19 percent. In air that dry, fine particles stay suspended longer and nothing on the ground holds them down.
The monsoon, which the National Weather Service dates from June 15 to September 30, adds a second source. The National Weather Service says dust storms and haboobs are most common in the Southwest and form from gusty thunderstorm outflow winds, and haboobs frequently occur in the Arizona desert around Phoenix. A single storm can drop a visible layer on patios, cars and window sills across the city.
Everyday dust is the slow, steady film of a dry climate. It settles on dark furniture, television screens, shelves and blind slats and is noticeable within a few days of dusting. It comes in on shoes, on pets and through tiny gaps around doors.
Storm dust arrives all at once. After a haboob, expect grit in window tracks and on sills, a coating on patio furniture, a sandy line just inside each exterior door, and a fresh layer on top of ceiling fan blades if windows or doors were cracked. Because it is heavier, it collects in tracks, corners and along baseboards rather than floating.
A few places collect far more than their share:
Nearly all Phoenix homes have air conditioning, and with about 111 days a year at 100 degrees or more, it runs for much of the year. A sealed, cooled house keeps out a lot of dust, but the system also moves whatever is inside around the rooms. Dusty supply vents and returns put particles back into the air every time the system cycles.
Keep vents and returns wiped, and follow the manufacturer's schedule for changing the system filter. Filter changes and duct work are homeowner or HVAC tasks; wiping the vent covers in place is cleaning work, and it is part of the One-Time Deep Clean.
Dust with a damp microfiber cloth instead of a feather duster, which only lifts fine desert dust into the air to settle again. Vacuum before mopping, never after. Shake entry mats outside at least weekly, and daily after a storm.
Through the dry months and the monsoon, a weekly or bi-weekly Recurring House Clean keeps surfaces, floors and reachable baseboards and blind slats under control. Once a year, after the monsoon ends on September 30, a One-Time Deep Clean clears the tracks, fans, vents and fixtures that routine visits do not reach. For scheduling, see the recurring cleaning guide.
The questions Phoenix homeowners ask most often about this topic, answered plainly.
TotalCare Cleaning will service Phoenix and surrounding areas with background-checked cleaners and is insured up to $1 million. Re-clean guarantee: if we missed something, tell us by the end of the next day and we come back to fix it. Beyond Clean. TotalCare.
