TUCSON, Ariz. — Triple-digit heat will hold across much of Southern Arizona through the coming week even as forecasters expect daily chances for afternoon and evening showers and thunderstorms across Southeast Arizona. The combination of persistently warm daytime highs and repeated storm chances is expected to produce day-to-day variability in both how widespread storms become and how intense they may be.
Loading post…
Monday morning is forecast to begin with another round of warm overnight temperatures. Tucson is expected to wake up to a low near 82 degrees, while many other valley communities will also remain unseasonably warm after dark. Vail, Sasabe and Green Valley are forecast to see overnight lows in the 70s, and much of Cochise County is likewise expected to remain in the 70-degree range through the early hours. Sierra Vista is predicted to have a morning low close to 72 degrees.
Afternoon temperatures are expected to climb back into the triple digits in a large swath of Southern Arizona on Monday and across much of the week. Tucson is forecast to reach a high near 105 degrees on Monday; many communities across Pima County are anticipated to exceed the 100-degree mark as daytime heating intensifies before the daily storm window. Higher-elevation locations will remain notably cooler than the valley, which will help preserve some localized temperature contrasts.
Forecast map showing tomorrow's high temperatures across the Tucson area — many locations in the triple digits (Tucson 105°F, Oro Valley 105°F, Catalina 103°F) while higher elevations like Mt. Lemmon remain cooler (78°F).
Across Cochise County, afternoon highs will be lower than the hottest valley locations but still well above seasonal norms in some places. Sierra Vista is forecast to warm to about 94 degrees, while communities toward the eastern part of the county such as Willcox and Bowie are expected to approach the century mark with highs near 99 degrees. Those numbers reflect a regional pattern in which the hottest readings will focus on lower-elevation desert and valley areas, while foothills and mountain locations remain comparatively mild.
The forecast guidance indicates temperatures running a few degrees above normal through the middle of the week, then trending warmer late in the week and into the weekend. Specifically, highs are expected to remain 2 to 5 degrees above average through midweek, with a warming to roughly 6 to 10 degrees above normal late in the week and over the weekend. Meteorologists point to that overall upward trend even as daily convective activity — the afternoon and evening storms — continues to interrupt the heat locally.
Storm activity is forecast primarily in the afternoon and evening hours each day, with the potential for varying coverage and intensity from one day to the next. Showers and thunderstorms are expected across Southeast Arizona through the next week; some afternoons may see only isolated activity while others could produce more widespread or stronger storms. Residents are being reminded that storm coverage and intensity can change quickly on a daily basis during this pattern.
For those seeking more detailed or near-term information, several resources are available to track conditions: hourly forecast products, seven-day outlooks, live radar, and official weather alerts. Additional weather resources include current temperature displays, maps showing today’s projected highs and lows, current dew point imagery, and precipitation and drought-monitor graphics covering recent periods. These tools provide situational awareness for both the persistent daytime heat and the afternoon-evening convective threats that are expected to continue through the week.
Posted July 26, 2026. This forecast covers the coming week and highlights the expected persistence of high temperatures coupled with daily storm chances across Southern and Southeast Arizona.
In response to the persistent triple-digit heat, the U.S. Department of Energy issued an emergency order authorizing the grid operator for Arizona and 16 other states to deploy idle power sources to help prevent outages. The Arizona Daily Star reported the action, highlighting infrastructure strain from the ongoing heat wave across the region.
The Department of Energy issued Emergency Order No. 202-26-23 on May 18, 2026 authorizing PJM Interconnection to deploy backup generation resources at data centers and other major facilities; that order was effective May 18–20, 2026 and explicitly allowed PJM to call on transmission owners and electric distribution companies to implement the direction as needed.
DOE issued several related Section 202(c) emergency orders in late June and July that expanded similar authorities for regional operators — including orders on June 30 (Nos. 202-26-32 and 202-26-33), an extension in early July, a July 14 order (No. 202-26-35) for PJM, and a July 20 order (No. 202-26-36) to the Southwest Power Pool — directing dispatch of specified units and allowing backup generation to be used as a last resort in those regions.
Those DOE orders were aimed at specific regional grids in the Eastern, Midwestern and parts of the central U.S.; PJM serves roughly 65 million people across 13 states and the District of Columbia and does not include Arizona, which is part of the Western Interconnection and is served by a different set of utilities and market arrangements.