The summer monsoon will remain active across southern Arizona through the remainder of the week and into the weekend, keeping the region on alert for severe thunderstorm activity and localized flash flooding. Thunderstorms that form in the unstable air mass are expected to produce hazardous conditions in spots, with the most significant threats identified as strong wind gusts, blowing dust and heavy rainfall over short periods. While not every community will see measurable precipitation, the pattern means most areas will have at least some chance of storms through the weekend.
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KGUN 9 First Warning Weather map showing Tuesday flood risk across southern Arizona, with moderate (yellow) and marginal (green) areas covering Tucson, Nogales and Sierra Vista.
Forecasters say the best chances for rain will remain to the east and south of Tucson, with communities in Cochise County and points close to the international border most likely to see heavier downpours. That said, the Tucson metro area still faces a decent probability of receiving storms, especially during the afternoon and evening hours when convective activity typically peaks during the monsoon season. Storm cells that develop can be highly localized, meaning one neighborhood may be soaked while areas just a few miles away remain dry.
The principal hazard from this round of monsoon activity will be damaging wind. Thunderstorms capable of producing 60 mph gusts or higher are a concern, and such winds can knock down branches, damage unsecured objects and reduce visibility when combined with dust. Blowing dust is an additional hazard in the drier stretches between storms; strong gusts can lift fine material and create rapidly changing visibility conditions across roadways and open areas.
Heavy rain in brief periods is the other primary threat with this weather setup. Intense showers and slow-moving storm cells can produce significant fall rates that lead to localized flooding, particularly in low-lying areas, washes and streets with poor drainage. The localized nature of these downpours makes inundation unpredictable on a small scale: flash flooding can occur after just a short, intense burst of rain, even if the broader region has seen only light totals. Residents in flood-prone neighborhoods and along arroyos and washes should be aware that conditions can change quickly where thunderstorms track slowly or repeatedly over the same area.
A car splashes through floodwater on a Tucson-area street during monsoon rains, illustrating the localized flooding risk described in the forecast.
Temperatures will remain elevated through the period, with daytime readings expected to stay in the low 100s across the southern Arizona basin. Nights will offer some relief but stay warm, with overnight lows forecast to fall into the mid to upper 70s. The combination of heat and humidity accompanying the monsoon pattern will keep atmospheric instability higher than typical for this time of year and will help fuel convective development when moisture and lift come together.
Not every town or neighborhood will experience severe weather during this stretch, but the active monsoon pattern increases the chance that some locations will be affected by damaging winds, heavy rain and blowing dust. Local forecasts are highlighting pockets of moderate to marginal flood risk across southern Arizona, including areas around Tucson, Nogales and Sierra Vista. Emergency services and weather officials typically monitor these evolving conditions closely during active monsoon episodes due to the speed at which storms can intensify and the uneven spatial distribution of rainfall.
Meteorologist Cuyler Diggs, who has been forecasting weather in southern Arizona since 2003 and who began weather broadcasting in 1996, notes that the monsoon is expected to stay active through the weekend. He advises that everyone in the region at least be prepared for the possibility of thunderstorms over the next several days and to pay attention to local forecasts. Those with story tips or local weather concerns can reach him by email at culyer.diggs@kgun9.com, or connect with him via social media.
In summary, southern Arizona will continue under an active monsoon pattern through the end of the week and into the weekend, with elevated chances for localized flooding, strong wind gusts and blowing dust. The heaviest rains are most likely to fall east and south of Tucson, but the metro area retains a meaningful risk of storms. Highs will remain around the low 100s while nighttime temperatures dip into the mid to upper 70s, and residents should remain alert to rapidly changing conditions as thunderstorms develop and move across the region.
The National Weather Service in Tucson issued an official Flash Flood Watch for portions of southeast Arizona (including Graham, Greenlee, Cochise and Santa Cruz counties) that was in effect on July 21, 2026, warning of localized rainfall amounts of roughly 1 to 3 inches and noting that saturated soils from earlier storms could increase runoff and flash‑flood potential.
In its forecast discussion the NWS explicitly urged residents in the watch area to monitor updates and be prepared to take action should Flash Flood Warnings be issued, emphasizing the heightened runoff risk given recent storms.
Separately, NWS products for the region showed an Extreme Heat Warning posted for a later period (July 30 through August 2, 2026) for parts of southern Arizona, indicating a brief stretch of more dangerous heat following the monsoon episodes described in the article.