Forget about that long run on South Mountain, folks. Today is absolute garbage for anyone wanting to push their limits outside.

🫁 Lungs & Joints Score?/10
    • Extreme Heat Warning is ON: We're looking at forecasted highs around 109-110°F (43°C) today. This isn't just "Phoenix hot"; this is "stay indoors unless you really like third-degree burns" hot. The National Weather Service has an Extreme Heat Warning in effect for Maricopa County, and frankly, anyone telling you to "power through" this heat needs their head examined.
    • Dusty Air Quality Hangover: While the general AQI might be sitting at a "moderate" 72 with PM2.5, don't let that fool you. We just had a High Pollution Advisory for PM10 (coarse particulate matter/dust) yesterday from thunderstorm outflows kicking up dust from storms in southern Arizona and Mexico. While it's supposed to improve, there's still lingering dust and a chance for more this evening, keeping that air thick with things you don't want in your lungs. AccuWeather even calls today's AQI "Poor" for sensitive groups.
    • Trails Are Actively Shut Down: The city isn't messing around with this heat. Key trails on South Mountain Park and Preserve, like the Holbert Trail and sections of the National Trail accessible from Pima Canyon, are restricted from 8 a.m. to 5 p.m. as part of the Trail Heat Safety Program. That means if you ignore the warnings and hit those trails mid-day, you're not just risking your own skin; you're risking our first responders who have to haul your dehydrated carcass off the mountain.

    Today's Environmental Breakdown

    | Factor | Level | Details I know that in Arizona, there's always a debate on whether to hit the trails or stick to the air-conditioned treadmill. So let's talk about July in Phoenix.

    Today isn't the day to push any boundaries outside. It's too hot, the air is hazy, and some of the best trails are literally off-limits for your own good. You'll thank me later.

    Workout Hazards in Phoenix

    Heatstroke is a Real, Deadly Threat

    Look, the current temperature might be around 94°F, but that's just the start. The forecast for today is a blistering 109-110°F (43°C), and those overnight lows aren't dropping enough to provide real relief. We're under an Extreme Heat Warning because these aren't just "uncomfortable" temperatures; they're dangerous and can lead to heat exhaustion and heat stroke extremely quickly.

    🚨

    Danger: Extreme Heat - Avoid Midday Outdoor Activity. With highs pushing 110°F and overnight lows staying elevated, your body can't recover. Strenuous activity during these hours is an emergency room visit waiting to happen. The National Weather Service Phoenix office itself uses criteria for these Extreme Heat Warnings that go beyond "typical July parameters" because the prolonged exposure to heat is so risky.

    Don't Breathe That Dust

    The air isn't doing you any favors either. We had a High Pollution Advisory for PM10 (dust) yesterday, and while it's predicted to improve over the weekend, there's still a risk of lingering dust and evening thunderstorms kicking up more. Your provided AQI of 72 might seem "Moderate" on paper, but when the dominant pollutant is PM2.5, and there's a dust advisory for PM10, it's a combo that's not great for your lungs. AccuWeather has even gone so far as to label today's air quality as "Poor" and "unhealthy for sensitive groups," recommending reduced time outdoors.

    ⚠️

    Warning: Moderate Air Quality with Dust. Even if it's "just" moderate, the presence of dust (PM10) can irritate your respiratory system, especially during exertion. Those tiny particles can lodge deep in your lungs. If you have any heart or lung conditions, or are just sensitive to poor air, stay inside.

    Trail Closures Aren't Suggestions, They're Rules

    As a PT, I'm all for movement, but not when it's going to land you on a stretcher. The City of Phoenix Parks and Recreation Department has implemented its Trail Heat Safety Program, which means certain popular trails, including the Holbert Trail on South Mountain, and access to the National Trail from the Pima Canyon Trailhead, are restricted from 8 a.m. to 5 p.m. on days with an Extreme Heat Warning. These aren't just polite suggestions; violating these closures can lead to fines and community service, and worse, put the lives of first responders at risk.

    💡

    Tip: Embrace the Early Morning or the Gym. If you absolutely must get activity in, do it before the sun truly takes hold—think 4-7 a.m. Otherwise, the treadmill, elliptical, or pool are your best friends today. Hydrate, hydrate, hydrate with water and electrolytes, and wear loose, light-colored clothing.

    Data grounded with KJZZ, NWS Phoenix, AccuWeather, FOX 10 Phoenix, and Hindustan Times from July 10-11, 2026.