PHOENIX — A notable shift in the weather pattern is bringing rising temperatures and the first hints of monsoon storm activity to Arizona this week, setting the tone for a hot end to June.
In the Phoenix Valley, early morning temperatures are starting out in the mid 70s to low 80s Fahrenheit (around 24–28°C), quickly climbing to an expected high of 103°F (39°C) this afternoon. That’s just below the seasonal average for this time of year in Phoenix, with clear skies and light winds adding to the dry desert heat.
In northern Arizona’s high country, winds remain brisk, with another breezy day on tap. A trough of low pressure continues to sweep across the Western U.S., delivering cooler-than-average temperatures to much of Arizona through the first half of the week, especially in elevated mountain towns. While conditions will stay mostly dry and sunny, southern and southeastern Arizona may begin to feel the effects of early monsoon storms, particularly during the afternoons and evenings.
By the latter half of the week, a strong ridge of high pressure begins to develop across the region. This will not only drive temperatures sharply upward, but also begin to pull monsoon moisture farther north. Mountain communities, particularly those along the Mogollon Rim and into northeast Arizona, may start to see scattered thunderstorm chances as early as Friday, continuing into the weekend.
Although the Valley is expected to stay dry through the workweek, the forecast grows more uncertain next week, with increasing potential for storm activity as monsoon conditions strengthen across more of the state.
As the high pressure system intensifies, temperatures in Phoenix will trend hotter. Expect highs near 104 to 105°F (40–41°C) by Tuesday and Wednesday, climbing to 108 or 109°F (42–43°C) on Thursday and Friday. By the weekend, highs could soar to a blistering 110 to 113°F (43–45°C), putting much of central Arizona under extreme heat conditions.
