Arizona Labor Day weekend: Weather service warns of runoff flooding

Labor Day may mark the unofficial end of summer for much of the country, but in metro Phoenix, where high temperatures last through October, that's far from true.

Many Arizonans will be taking advantage of the long holiday weekend, traveling both by air and by road — even when Arizona is seeing average gas prices 50 cents above the national average.

One good thing? No major road closures were scheduled for Arizona highways. Still, drivers were being asked to plan ahead as congested roads are expected in the next couple of days.

Lower temperatures were expected throughout the holiday weekend, with some chances of rain at the start of the weekend, before they pick back up starting Monday.

Here's the latest on traffic, weather and any major events happening during the weekend.

Heavy traffic lingers on I-10 after lane clears

The left eastbound lane of Interstate 10 reopened near 339th Avenue following a vehicle fire that blocked all lanes, according to the Arizona Department of Transportation.

Authorities said there were heavy delays in the area and crews were working to clear the vehicle "as quickly as possible."

— Laura Daniella Sepulveda

Crashes, fires block lanes on I-10, SR 95

Serious crashes and vehicle fires were blocking state freeways as of Sunday afternoon, according to the Arizona Department of Transportion.

Vehicle fires forced closures on eastbound Interstate 10 near 339th Avenue and on State Route 95 northbound near Mohave Road in Parker.

Other freeways were blocked due to serious crashes, according to ADOT.

State Route 377 south of Holbrook was blocked near milepost 18. Another serious crash was reported on the westbound lanes of State Route 66 north of Kingman, at milepost 77.

The was no estimated time of reopening.

— Laura Daniella Sepulveda

Cool morning temperatures lower than normal, expected to continue

Phoenix residents woke up to pleasant and abnormal temperatures for a Sunday morning in September as the lows throughout the Valley bottomed out in the 70s.

Phoenix's low for Sunday morning was 80 degrees, which was 2 degrees below normal for this date. The forecast low for Phoenix on Labor Day is 75 degrees, meaning Monday morning is likely to be just as cool.

— Ellie Willard

Despite storm activity waning, weather service warns of runoff flooding

According to the National Weather Service in Phoenix, storm activity over La Paz County and northwest Maricopa County decreased considerably with light remnant showers.

However, runoff could still be expected to be a problem with flooding.

— Lillian Boyd

Flash flood warnings issued for Maricopa and Coconino counties

The National Weather Service in Phoenix has issued a flash flood warning for Maricopa County from 5:22 p.m. until 9:15 p.m. Saturday.

The National Weather Service in Flagstaff has issued a flash flood warning for Coconino County from 5:30 p.m. to 6:30 p.m. Saturday.

The weather service advised areas north of Humphreys Peak in Coconino County to be on alert. This included Humphreys Peak, Abineau Canyon Trailhead, Agassiz Peak, Aspen Corner Trailhead and Bismarck Lake.

The weather service advised motorists to turn around if they come across flooded roads. "Most flood deaths occur in vehicles," the weather service said.

— Abigail Celaya

Phoenix Sky Harbor sees lower than normal temperatures

The National Weather Service reported that the high temperature at Phoenix Sky Harbor Airport on Saturday was 99 degrees. This is 5 degrees below average or normal for this time of year.

The normal, average temperature for Sept. 2 is 104 degrees.

— Abigail Celaya

Yuma placed under flood watch

If you live in Yuma, you may want to limit your activities during the afternoon Saturday.

The National Weather Service has issued a flash flood warning for Yuma, which was in effect from 12:43 p.m. to 3:45 p.m. Saturday.

In a special weather statement, the weather service said that conditions are favorable throughout the Valley this afternoon for scattered thunderstorms that may produce brief heavy rainfall and wind gusts of up to 30-40 mph.

— Abigail Celaya

'If you haven't left yet, wait it out': Holiday traffic delays on I-17

Arizona Department of Transportation reported holiday traffic on Interstate 17 around midday on Saturday between Anthem and New River.

“If you haven’t left yet, wait it out,” the agency advised.

— Lillian Boyd

Storm activity begins west of Phoenix, expected through afternoon

The western parts of the Valley saw storm activity late Saturday morning. The National Weather Service in Phoenix predicted the storms will continue through the afternoon.

"If you do get under one, expect brief heavy rainfall and wind gusts up to 40 mph," the weather service said in a post on X, formerly known as Twitter.

— Lillian Boyd

National Weather Service: West Valley to see thunderstorm activity

Temperatures were expected to remain below normal with afternoon highs failing to reach 100 degrees, according to the National Weather Service in Phoenix.

The weather service forecast thunderstorm activity in western Maricopa County through the Lower Colorado River Basin. Drier conditions were expected to take over by the end of the Labor Day weekend, and temperatures will begin to trend upward by the middle of next week.

— Lillian Boyd

Western Arizona sees flash flooding risk

Friday brought an increase in storm chances for Yavapai and western Coconino counties with downpour at its highest probability Friday through Saturday night, according to the National Weather Service in Flagstaff.

The likelihood for storms will drop Sunday and next week will be precipitation free, the weather service said.

— Jose R. Gonzalez

I-10 westbound lanes now open near Gila River

The westbound lanes of Interstate 10 reopened near the Gila River Indian Community, according to the Arizona Department of Transportation's X/Twitter account.

The lanes had been closed because of a crash at milepost 173, according to ADOT.

The lanes reopened about 4:20 p.m., according to ADOT.

— Aidan Wohl

Rain spotted in Scottsdale on Friday afternoon

The Arizona Department of Transportation posted pictures on X, formerly known as Twitter, showing vehicles driving through rain-soaked roads on Loop 101 in Scottsdale.

The agency urged drivers to slow down, turn on their headlights and leave braking room for the vehicles in front of them.

The precipitation follows Thursday night's thunderstorms, which knocked out power for thousands across the Valley.

— Staff reports

Cool temperatures continue on Saturday, chance of morning showers

Just in time for Labor Day weekend, the cooling streak of temperatures continues across the Valley on Saturday.

The National Weather Service forecast a high of 96 degrees on Saturday afternoon with a low of 82 degrees that evening. A 40% chance of showers and thunderstorms was also possible before noon, following showers expected Friday night.

— Staff reports

No freeway closures planned in Arizona for Labor Day weekend

As Labor Day weekend travel kicks off in Arizona, there's some good news for motorists: the Arizona Department of Transportation will be pausing their usual freeway improvement projects.

"ADOT and its contractors will not schedule any full construction closures along state highways from Friday afternoon, Sept. 1, to early Tuesday morning, Sept. 5. Highways that lead to the high country, beaches and destinations such as Las Vegas are expected to be busy on both Friday and Monday afternoons," ADOT said in a news release.

The department urges that those headed in any direction to stay focused on the road ahead, allow for extra travel time and "expect the unexpected" in addition to being alert to highway conditions. The weather and upticks in travel will likely spell for heavier traffic conditions.

Some stretches already have existing work zones in place, which drivers need to be aware of, such as southbound Interstate 17 being narrowed to one lane in areas along the 30-mile stretch south of Flagstaff.

— Kye Graves

Thousands of metro Phoenix residents without power

As of Friday morning, thousands of Phoenix-area residents continued to experience outages.

An SRP spokesperson said that about 3,900 people were impacted, and about 2,000 APS customers were also impacted.

SRP customers experiencing outages longer than five hours may be eligible for ice reimbursement to help preserve perishables.

The outages come as Maricopa County registered at least 47 additional heat-associated deaths this week, bringing the total count for 2023 to 180, while 330 deaths remained under investigation.

— Kye Graves

More: Thousands still without power throughout Phoenix-area following overnight thunderstorms

Strong thunderstorms expected in Phoenix area, again

As thousands of Valley residents continued without power after Thursday night's severe dust and thunderstorms, the National Weather Service said the same can be expected as we head into the long holiday weekend.

Strong to severe thunderstorms were possible starting in the afternoon, the weather service said, bringing in strong winds, small hail, lightning and heavy downpours

Most impacted areas were expected to be in south and central Arizona, seeing between 1 to 2 inches of rain Friday.

— Joanna Jacobo Rivera

Best times to leave Phoenix for your Labor Day weekend road trip

If you're driving on Labor Day weekend in Arizona, make sure you plan for roadways congested with everyone else who planned road trips for Labor Day weekend.

The heaviest traffic in Arizona is expected late Friday and Monday afternoons, with the heaviest travel expected between 2 and 7 p.m., said Doug Nintzel, spokesman for the Arizona Department of Transportation.

Saturday morning tends to be slightly less busy as many drivers will likely use Friday to get to their destination, Nintzel said.

Lighter traffic conditions were expected on Saturday and Sunday before people start their return journeys on Monday, he said.

— Michael Salerno

This article originally appeared on Arizona Republic: Labor Day travel tips: Arizona traffic, road and weather updates