Don't let the current clear skies fool you; today's a deceptively tricky day to hit the trails hard in Rancho Cucamonga. While the morning might feel pleasant, things are warming up fast, and the air quality is, well, not exactly pristine.
- That "Clear" weather is hiding some rising ozone levels, meaning those deep, satisfying breaths you crave on a run might feel less refreshing, especially as the day wears on.
- You might start cool, but today's forecast has us pushing into the low 80s°F (around 27-29°C), which isn't exactly prime long-distance weather unless you're an early bird or a heat junkie.
- Some of our best mountain escapes are still shut down, seriously limiting your options for elevation gain without risking a fine or, worse, an injury.
Pollen Breakdown (Low-Risk Day, at Least)
| Pollen Type | Level |
|---|---|
| Tree | Low |
| Grass | Low |
| Weed | Low |
The Rundown: Ozone Rising & Trails Still Shut
Alright, let's talk turkey. The good news is pollen is low, so if you're one of those folks who sneezes your way through spring, you've got a small win today. But don't get too comfortable. Our local air quality, sitting at a moderate AQI of 60 with ozone as the dominant pollutant, is already a red flag for anyone with sensitive lungs. As that temperature climbs into the low 80s today, ozone tends to bake, and that AQI number might just follow suit. So, if you're planning a long haul on the Pacific Electric Trail, think about shifting it to the super early morning.
Ozone Alert: Don't Push It Too Hard
An AQI of 60, especially with ozone, means sensitive groups should probably limit prolonged outdoor exertion. Even if you consider yourself a human tank, that gnawing feeling in your chest later isn't worth bragging rights.
Now for the real kick in the teeth: those glorious mountain trails we all love? Many are still off-limits. If you had your heart set on Cucamonga Canyon for some waterfall chasing or a serious climb up Cucamonga Peak, forget it. The U.S. Forest Service has Cucamonga Canyon, including the infamous Sapphire Falls, locked down until at least May 2026 due to ongoing safety concerns and, let's be honest, years of abuse from folks who treated it like their personal trash can. And Cucamonga Peak Trail 7W04? Closed due to storm damage as of late last year, and high elevation hiking this time of year isn't for the faint of heart or the unprepared anyway.
Cucamonga Canyon & Peak: STAY OUT!
Seriously, folks. Cucamonga Canyon is still closed to public use until May 2026. Don't be that person. Same goes for Cucamonga Peak Trail 7W04 due to storm damage. There are reasons for these closures; ignoring them is dumb and dangerous.
If you're wondering what is open, stick to the flatter, paved routes early. The Pacific Electric Trail is generally a safe bet, and while it's not the wilderness experience of the canyon, it's better than risking a rescue or a ticket. We're also seeing some field investigation work along I-15 for the Brightline West high-speed rail, so keep an eye out for construction-related detours if you're near that corridor.
Hydration & Timing are Key
With temps hitting the 80s, proper hydration isn't just a suggestion, it's a requirement. Plan your runs for before 8 AM or after 6 PM to avoid the worst of the heat and ozone buildup. And always tell someone where you're going, especially if you insist on exploring less-traveled areas.
Data grounded with Google Search from February 26, 2026.