Phoenix weather shifted quickly Monday evening as scattered showers and thunderstorms moved into the Valley, with a First Alert Weather Day declared for Monday and a better chance of more widespread storms arriving late at night. Some parts of Phoenix and communities east of the Valley saw rain around 5: 30 p. m., while forecasters warned that a few storms could become severe overnight.
What is happening with Phoenix Weather tonight in the Valley?
Across the Phoenix area, the window for storms widens late Monday evening and continues on and off overnight into the pre-dawn hours of Tuesday. The main concern is that one or two storms could turn severe, with potential for hail and strong wind gusts. Central and southern Arizona, including the Valley, also sits in a “Marginal Risk” area for severe storms flagged by the Storm Prediction Center, a level that signals the possibility of thunderstorms capable of damaging wind gusts and small hail.
Timing details vary by forecast, but the pattern is consistent: isolated activity can pop up earlier in the evening, with a more organized round of showers and thunderstorms favored later at night. Rainfall totals are expected to vary widely across the Valley, with some spots picking up only a light amount while others see higher totals under heavier downpours.
How much rain is expected, and why will it be uneven?
Forecast totals through Tuesday morning in the Valley range from about a tenth to a quarter of an inch, with higher amounts possible in the heaviest downpours and across higher terrain. Another forecast breakdown describes a sharper neighborhood-to-neighborhood contrast: some Valley locations near around 0. 05 inches, while others could approach 0. 25 inches. That spread reflects how thunderstorms can concentrate rainfall over narrow corridors, leaving nearby areas much drier.
At Sky Harbor, official rainfall to date for 2026 is 0. 26 inches, listed as 1. 78 inches below average. Separate climate normals also point to a longer-term drying trend in Phoenix rainfall averages: the average monsoon rainfall in Phoenix is 2. 71 inches for 1981–2010 versus 2. 43 inches for 1991–2020, and the average yearly rainfall is 8. 03 inches for 1981–2010 versus 7. 22 inches for 1991–2020.
When does the storm move out, and what comes next?
By Tuesday morning, a few showers may linger mainly across higher terrain east of the Valley, while much of Arizona trends drier by Tuesday afternoon. Sunshine is expected to increase Tuesday, with Valley highs in the mid to upper 70s after a cooler stretch. That cooler air does not last long.
Temperatures rebound quickly midweek, reaching the low to mid-80s on Wednesday. From there, a significant warmup is expected late this week into the weekend: Valley highs are projected to reach the low to mid-90s on Thursday and hold in the mid-90s from Friday through the weekend, with some daily high-temperature records potentially in jeopardy. Forecasters also note that some long-range models suggest highs could climb above 100 degrees by the middle of next week, though confidence in those numbers remains low.
If Phoenix does reach 100 degrees or higher next week, it could challenge the earliest 100-degree day on record. The standing record cited in multiple forecasts is March 26, set in 1988.
What should residents watch for from late evening into early Tuesday?
For the immediate forecast period, the main message is to stay alert for rapidly changing conditions overnight: heavier bursts of rain, gusty winds, and small hail are all on the table in the strongest storms. The storm system crossing southern Arizona overnight is expected to pull moisture into the state, supporting scattered showers and a few thunderstorms, with southern and southeastern Arizona holding the best chance of rain overall.
In the Valley, the most likely impacts concentrate late Monday night into early Tuesday. By Tuesday afternoon, the pattern shifts toward drying and warming as high pressure begins to build back in. That setup points to a quick transition from storm chances to heat concerns, with the late-week warmup bringing temperatures well above typical levels and raising the possibility of new daily heat records.
As Phoenix weather moves from overnight storms to rapidly climbing temperatures, the week’s storyline becomes one of fast swings: a burst of active weather now, then a return to sunshine and heat that could press toward triple digits again soon.
