Tucson's monsoon season (JulyβSeptember) delivers roughly half the city's 12 annual inches of rain in concentrated storms β Pima County has recorded over three inches in under two hours. That intensity overwhelms roof drainage and pushes water into wall cavities through stucco cracks dried out during pre-monsoon months.
HVAC systems are Tucson's second major mold driver. Summer highs above 100Β°F mean aggressive air conditioning runs all season, generating condensate at air handlers and in ductwork. Evaporative coolers introduce moisture directly into the air supply and can sustain elevated wall-cavity humidity when water lines or overflow drains leak.
Ask for an IICRC-certified inspector who uses thermal imaging and air sampling with an outdoor control. If results show Condition 2 or 3 contamination under the S520 standard, mobilize a remediation crew within 48 hours to prevent further spread.