Phoenix, Arizona – Desert temperatures could approach 100°F by Thursday afternoon in Phoenix, as a powerful high-pressure ridge settles across the western United States and pushes Arizona into an early-season heat surge during the first full days of spring.
According to the National Weather Service Climate Prediction Center, the pattern expected Wednesday through Sunday, March 18–22, strongly favors above-normal temperatures across the Southwest, with Arizona running 15 to 25 degrees above typical mid-March levels. Phoenix could climb into the upper 90s, while Tucson and Yuma may reach the mid to upper 90s during the peak of the heat late in the week.
The warming trend will arrive alongside very limited rainfall chances. Forecast outlooks show below-normal precipitation probabilities across Arizona and much of the interior West, keeping skies mostly clear and allowing daytime temperatures to climb quickly each afternoon.
Dry air and strengthening winds could also increase wildfire concerns across desert and brush-covered terrain. Afternoon wind gusts between 25 and 40 mph are possible in open desert corridors and along Interstate 10 and Interstate 17, while humidity levels may fall below 15 percent during the hottest part of the day.
Outdoor activity will feel more like early summer than early spring. Hikers across the Phoenix metro area, including trails around Camelback Mountain and South Mountain Park, may face heat exposure risks during peak afternoon hours.
Elsewhere across the country, conditions remain more typical for the season. New England states, Michigan, and Florida are expected to see near-average temperatures, while northern New England, the Pacific Northwest, and parts of South Florida show a greater chance for above-normal rainfall during the same period.
The western heat surge is expected to peak late in the week before larger weather pattern changes potentially shift conditions heading into the following week.
