Arizona's monsoon season runs from June 15 to September 30. It brings sudden heavy rain, flash floods, dust storms and strong winds. To protect your home, clear roof drains, check that the yard slopes away from the house, protect low doorways, move valuables off the floor, and consider flood insurance well before storms arrive.
Key takeaways
- Monsoon season officially runs June 15 to September 30.
- Flood insurance usually takes 30 days to start. Buy it before the season.
- Most monsoon water enters through low doors, garages and blocked roof drains.
- Never drive into a flooded wash. Arizona can bill drivers for their rescue.
When is monsoon season in Arizona?
The National Weather Service defines monsoon season in Arizona as June 15 through September 30. The heaviest storms usually come in July and August, when moist air flows in from the south and builds afternoon and evening thunderstorms over the mountains and desert.
Why does Apache Junction flood during monsoon storms?
Apache Junction sits below the Superstition Mountains, with natural washes running through neighborhoods. Hard, dry desert soil sheds rain instead of soaking it up, so water rushes into those washes within minutes. When they overflow, they flood streets, yards and sometimes homes.
On July 28, 2022, the National Weather Service reported washes overflowing their banks across Apache Junction, closing roads and flooding or surrounding several homes. Local reports described more than an inch of rain in much of the city, with one location reporting about 2.5 inches.
What damage does flooding cause to a home?
| Area | What floodwater does |
|---|---|
| Drywall and insulation | Wicks water up the wall, swells and grows mold. Usually cut out above the water line. |
| Flooring | Soaks carpet and pad, lifts laminate, loosens tile and swells wood. |
| Cabinets and furniture | Particleboard swells and falls apart. Upholstery holds contamination. |
| Electrical and HVAC | Wet outlets, panels and ductwork become safety hazards. |
| Foundation and yard | Erodes soil and swells clay under slabs and patios. |
| Health | Floodwater carries bacteria, silt and debris, so it is treated as contaminated water. |
Can flooding cause foundation damage?
Yes. Fast-moving water can wash soil out from under the edges of a slab or patio. In clay and caliche soils common in the East Valley, heavy soaking after a long dry spell can make the ground swell, then shrink as it dries. Repeated cycles can crack slabs and stucco. Keep water draining away from the house, and watch for new cracks after big storms.
Monsoon water came inside? Floodwater needs cleaning and drying, not just fans.
Call: (856) 481-6893How do you protect your home before monsoon season?
On the roof
- Clear roof drains, scuppers and gutters of leaves, dust and debris.
- Check flat-roof coatings and flashing around vents, coolers and skylights.
- Secure swamp coolers and anything loose that wind can lift.
Around the house
- Make sure soil and gravel slope away from the foundation.
- Clear drainage swales, culverts and yard drains.
- Seal gaps under doors that face downhill, and have sandbags ready if your home has flooded before. Many Valley cities offer sand and bags during monsoon season, so check with your city.
- Trim trees and large shrubs that could fall on the roof.
Inside
- Move valuables, papers and electronics off garage and floor level.
- Know where your main water shutoff and electrical panel are.
- Take photos of your home and belongings for insurance records.
Insurance
Standard homeowners policies do not cover flooding from outside. Flood coverage through the National Flood Insurance Program usually has a 30-day waiting period, so buy it before June. Read what homeowners insurance covers in Arizona.
What should you do if monsoon water gets inside?
- Stay out of water if the power is on. Turn off the breaker only if you can reach it safely.
- Photograph the water line on the walls and every damaged item.
- Wear boots and gloves. Treat the water as contaminated.
- Remove mud and standing water as soon as it is safe.
- Call a restoration provider to remove soaked materials, disinfect and dry. See our flood damage restoration page and the restoration process.