MOST ACCURATE FORECAST: Excessive Heat Warning and monsoon storm chances

Posted at 5:39 AM, Jul 20, 2022
and last updated 2022-07-21 01:43:06-04

PHOENIX — The heat is on!

Excessive Heat Warnings are in effect for the Valley, and much of southern and western Arizona, as we wrap up the week. This heat alert is also in effect for some of the lower elevations of northern Arizona.

Temperatures will approach the 110-degree mark in Marble Canyon, Glen Canyon and the lower elevations of the Grand Canyon.

Places like Chino Valley, Mayer, Cottonwood and Camp Verde are expected to soar well into the triple digits Thursday and Friday, too.

Valley temperatures will top out near 114 degrees and places like Lake Havasu City and Bullhead City will climb well above 115 degrees.

So, we will be in ABC15 Weather Action mode Thursday and Friday. Take action to stay safe in these dangerously hot temperatures. Stay hydrated and stay inside as much as possible during the day. Remember to bring your pets inside and never leave kids or pets in your car for any length of time.

So far this year, Phoenix has hit 110-degrees or higher 18 times. The new 30-year average is 21 days per year at 110 or more. That's up from our previous 30-year average of 19 days a year as our climate gets warmer.

We have 2 more days in the forecast this week above 110 degrees in Phoenix before temperatures drop this weekend.

There's not much relief from the heat overnight either. Valley lows are only dropping into the upper 80s to low 90s through the end of the week.

We're also monitoring air quality as ozone pollution in the Valley reaches unhealthy levels this week. An Ozone High Pollution Advisory is in effect through Thursday with an Ozone High Pollution Watch on Friday.

If you have any respiratory conditions, like asthma or COPD, limit your time outside or you could have difficulty breathing.

Monsoon storm chances will mainly be confined to the Mogollon Rim, White Mountains and southeastern Arizona on Thursday and Friday.

Gusty winds, lightning and heavy downpours continue to be the main threats, but there's also a risk for flash flooding near our wildfire burn scars.

Here in the Valley, there's just a slight chance of isolated storms through the end of the week.

Over the weekend, high pressure will shift back toward the Four Corners allowing a lot more monsoon moisture to flow in. That will increase storm chances on Saturday, Sunday and early next week.

As storm chances increase, temperatures will drop. Expect Valley highs near 109 degrees on Saturday, 106 on Sunday and 102 on Monday.


2022 Rainfall totals:

Sky Harbor Official Rainfall: 0.91" (-2.53" from average)

Valley Average (Phoenix Rainfall Index): 1.21"


Daily rainfall reports from all across the Valley can be found here.


Average Monsoon Rainfall in Phoenix (1981-2010): 2.71" of rain

NEW Average Monsoon Rainfall in Phoenix (1991-2020): 2.43" of rain

Average Yearly Rainfall in Phoenix (1981-2010): 8:03" of rain

NEW Average Yearly Rainfall in Phoenix (1991-2020): 7.22" of rain

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