Look, if you absolutely have to get outside today, you're going to earn those miles. But honestly, it's not looking great.
- Scorching Heat Advisory: We're under a Heat Advisory until 10 PM tonight, with temps expected to push into the mid-90s to over 100°F (35-38°C) later today. Don't be a hero.
- Guadalupe River Trail Headaches: Active sediment removal means a section of the East trail from Trimble Road to Airport Parkway is closed during peak daytime hours. Expect detours and construction crews.
- Sneaky Ozone: While the official AQI is "Good," some forecasts for sensitive groups are leaning towards "Poor" or "Moderate" due to ozone. You'll be breathing that in, hot and heavy.
The Brutal Reality: Heat, Haze, and Half-Closed Trails
Alright, San Jose, let's talk turkey. It's 31.0°C (87.8°F) out there already, and the day is just getting started. The National Weather Service isn't kidding around; we've got a Heat Advisory plastered across the Santa Clara Valley until 10 PM tonight. They're talking mid-90s to even 105°F (35-40.5°C) in some spots. This isn't just "a bit warm" for your afternoon run; this is "stay indoors unless you really like flirting with heat stroke" territory. Hydration is non-negotiable. If you're out there without a Camelbak full of water, you're doing it wrong.
DANGER: Extreme Heat Warning in Effect! A Heat Advisory is active until 10 PM PDT tonight with temperatures forecasted to hit 95-105°F (35-40.5°C). Limit strenuous activity, especially between 10 AM and 3 PM. Seek shade and hydrate constantly. Check on elderly neighbors and those without A/C.
Then there's the air. The official AQI sits at a breezy 25, listed as "Good," with ozone being the dominant pollutant. Sounds great, right? Except AccuWeather is predicting "Poor" air quality for today, especially for sensitive groups, and other sources are calling it "Moderate." Call me cynical, but when you're pushing hard and sucking in lungfuls of hot air, that "good" ozone can turn into a real irritant. Your lungs will know the difference, even if the city website doesn't.
| Pollen Type | Level (San Jose) |
|---|---|
| Overall | Moderate |
Tip: Watch for Ozone Irritation Even with a low AQI, ozone can be an irritant, especially during high-intensity exercise in the heat. If you're sensitive, consider shifting your workout indoors or to early morning/late evening.
And let's not forget the obstacle course that some of our beloved trails have become. If your route includes the Guadalupe River Trail near the airport, listen up: Valley Water is doing sediment removal from Trimble Road to the Airport Green Parking Lot. That means the east trail from Trimble Road to Airport Parkway is shut down Monday through Friday, 7:30 AM to 3:00 PM, until tomorrow. So, yeah, you'll be dodging flaggers and finding detours if you're trying to get a midday workout in. It's not the apocalypse, but it's certainly not ideal when you're just trying to get your miles in.
TRAIL CLOSURE: Guadalupe River Trail (East) The east side of the Guadalupe River Trail between Trimble Road and Airport Parkway is CLOSED weekdays from 7:30 AM to 3:00 PM for sediment removal until October 9th. Plan for detours.
So, if you're still determined to sweat it out, know what you're up against. Stay hydrated, stay alert for those detours, and maybe, just maybe, question your life choices if you're running at noon.
Data grounded with AccuWeather, Weather Underground, and Valley Water from October 08, 2026.