Phoenix braces for rare March heat as Cactus League day games face triple-digit forecast

PHOENIX — By midafternoon next week, the thermometer outside several Phoenix-area ballparks could be flirting with 105 degrees. The games on the schedule, however, still read like any other March day in the Cactus League: first pitch at 1:05 p.m., sunshine expected.

Forecasters with the National Weather Service in Phoenix are warning that a blast of early-season heat is poised to push high temperatures in the metro area into the triple digits between March 17 and March 20, weeks earlier than normal. If the forecast verifies, Phoenix could not only log its earliest 100-degree day on record but also challenge all-time March temperature marks — right in the middle of Major League Baseball’s spring training schedule.

Triple digits, weeks ahead of schedule

The prospect is turning what is usually marketed as “perfect spring weather” into a real-time stress test for how teams, local officials and fans handle heat normally associated with July.

“Not only will all-time record March temperatures likely be broken but also the earliest occurrence of 100 degrees in Phoenix,” the Weather Service office wrote in a forecast discussion this week, noting that daily highs could run 20 to 25 degrees above normal for mid-March.

Meteorologist Katherine Berislavich said guidance shows a roughly 55% chance of temperatures exceeding 105 degrees on Wednesday, March 18, climbing to 70% on Thursday and 85% on Friday.

The numbers stand out in a city that, on average, does not reach 100 degrees until early or mid-May. The earliest triple-digit day on record is March 26, 1988 — also the only March day that has ever hit 100 since record-keeping began. Breaking that mark by nearly a week would underscore how quickly the region’s heat season is creeping forward on the calendar.

Spring training in the hottest part of the day

This time, it is arriving as 15 of the sport’s 30 clubs go through spring training at 10 mostly open-air stadiums across the Valley, from Scottsdale and Mesa to Glendale, Goodyear and Surprise. A full slate of day games is scheduled at those venues through next week, along with special Spring Breakout prospect showcases beginning March 19.

The Cactus League, now in its 79th season, is a major draw for out-of-state visitors and a substantial piece of the local economy. A study commissioned by league officials estimated spring training generated about $764 million in economic impact for Arizona last year, with nearly six in 10 attendees traveling from outside the state.

Many of those visitors deliberately seek out afternoon games to sit in the sun. Typical start times hover around early afternoon, when the sun angle and temperatures are near their peak.

That tradition is running headlong into an increasingly harsh climate.

“We know it’s going to be smoking hot next week, but we’ve got to get work done,” Arizona Diamondbacks manager Torey Lovullo said when asked about the forecast. “There’s nothing that you can do sometimes to replace going out and actually doing it. We’ll find a way to get it done and make sure these athletes are healthy, strong, hydrated and ready for the next day. But we may make some adjustments.”

Those adjustments, team staff and league observers say, could include moving more workouts to early mornings, limiting time in full sun during practice and expanding cooling opportunities in dugouts and clubhouses. Clubs can also change game times on their own. Major League Baseball does not centrally schedule spring training; each team controls its home dates and first-pitch times, and in theory could shift a day game to an evening start.

As of Friday, there was no broad indication of wholesale schedule changes for the hottest days, and no publicly announced leaguewide heat protocol for exhibition play.

In other sports, including professional soccer, governing bodies have adopted detailed rules that rely on wet bulb globe temperature — a measure that blends heat, humidity, sun and wind — to mandate cooling breaks, shorten matches or postpone play when conditions become dangerous. MLB has adjusted first-pitch times for some regular-season games in recent summers, particularly during heat waves in the Midwest and East, but it has not outlined a universal standard.

Health risks spike early in the season

The Weather Service, which uses a color-coded “HeatRisk” tool to flag dangerous days, stresses that early-season hot spells can be particularly hazardous because people are not yet acclimated. Agency guidance notes that health impacts, including spikes in emergency room visits, become more pronounced during periods labeled as having “major” or “extreme” risk, even at temperatures locals might tolerate later in the year.

“Temperatures that might feel manageable in July can be much more dangerous in May, when people have not had time to adapt,” the Phoenix office says in its heat-safety materials. March heat at those same levels comes even earlier in the season.

Public health officials in Maricopa County have been grappling with rising consequences of that trend. The county recorded 645 heat-associated deaths in 2023 and 602 in 2024, both record highs since tracking began in 2006. Many of those deaths involved unsheltered individuals or residents in neighborhoods with limited access to shade and air conditioning.

The coming heat wave will test systems that typically gear up later in spring. In recent years, the city of Phoenix and regional partners have opened more than 200 cooling centers and hydration stations at the height of summer. Early spikes in temperature can strain those efforts, especially if resources and staffing are still scaling up.

Inside the ballparks: shade, water and worker exposure

Inside the ballparks, operators say they already plan around hot weather, even in March. Most Cactus League stadiums allow at least one factory-sealed water bottle per person, and many sell inexpensive bottled water at concession stands. Some facilities have misting fans and shaded concourses, and most list medical and first-aid stations in their stadium guides.

At Tempe Diablo Stadium, spring home of the Los Angeles Angels, guests are permitted to bring in clear plastic bottles of water or sports drinks within size limits. The park, like others, bans glass and frozen items but promotes the presence of first-aid staff on the concourse.

Shade, however, is uneven. Some venues, such as Phoenix Municipal Stadium, offer considerable covered seating in upper rows by early afternoon. Others have large blocks of seats fully exposed to the sun for most of the game. Fans swapping advice on message boards often urge newcomers to seek out shaded sections, wear light clothing and wide-brimmed hats, and be wary of metal bleachers and railings that can become hot to the touch.

The risks are not limited to ticket holders. Ushers, security staff, concession workers and parking attendants often spend many hours outdoors with limited ability to leave their posts. Many are older adults or seasonal workers — demographics state and local health officials identify as more vulnerable during heat events.

Meanwhile, asphalt surrounding the stadiums can easily exceed 140 degrees in direct sun, making the walk from distant parking spots to the gate — often with children or older relatives in tow — a challenging part of the outing.

A hotter baseline, and pressure to adapt

The forecast comes after back-to-back summers that have drawn national attention to Phoenix’s heat. In 2023, the city logged the hottest month ever recorded in any U.S. city, with July’s average daily temperature — combining highs and lows — above 100 degrees and 55 days that summer reaching at least 110. In 2024, Phoenix endured 113 consecutive days with highs at or above 100 degrees and 70 days of 110 or higher, setting additional records.

Climate scientists say the increasing frequency, intensity and duration of heat waves in the Southwest is consistent with long-term warming driven by human-caused climate change. Local climate assessments have documented a steady rise in both daytime and nighttime temperatures over recent decades, along with more days each year above 100 and 110 degrees.

For the Cactus League, the implications extend beyond a single week. If triple-digit heat in March becomes more common, teams and host cities may have to consider more fundamental changes: shifting more games under the lights, investing in additional shade and cooling infrastructure, or rethinking how long fans are expected to sit in full sun.

Economically, there are tradeoffs. Moving games later could increase costs for lighting and staffing and alter long-standing traditions of daytime spring baseball that help drive concessions and tourism. Failing to adapt, on the other hand, risks depressing attendance, straining medical and emergency services and amplifying health risks for fans and workers.

Next week, the choices will play out one game at a time. On paper, the schedule looks routine: the Chicago Cubs in Mesa, the San Francisco Giants in Scottsdale, the Texas Rangers in Surprise, all under clear desert skies. In the stands, fans will be reaching for sunscreen and water as the numbers on the scoreboard edge toward triple digits — and as a spring ritual confronts the kind of heat that used to wait until summer.