Today's weather is a bit of a mixed bag; your lungs will thank you, but your usual routes might be a frustrating maze.
- Your lungs are in luck: The Air Quality Index is a breezy 42, and pollen is officially on vacation. Breathe easy, St. Louis.
- Don't let the clear skies fool you – it's 5.5°C out there, so layers are your best friend. Also, keep an eye out for potential dense fog lingering from early this morning, especially if you're hitting the pavement at dawn.
- Heads up, trail runners and cyclists: widespread closures and hazardous conditions mean you'll need a backup plan, or three.
The Rundown
Alright, St. Louis, let's talk brass tacks. It's a "bundle up and go for it, but be smart about where you go" kind of day. The good news? Your respiratory system is getting a break. With a "Low" pollen count and a fantastic Air Quality Index of 42 (that's green, folks, green!), you won't be snotting your way through your workout or gasping for air. The dominant pollutant is just inhalable particulate matter, which is pretty standard background noise and not a major concern at this AQI.
The weather is chilly but clear at 5.5°C. That's perfectly runnable if you layer up correctly. Think base layer, maybe a light mid-layer, and a windbreaker. Gloves and a hat aren't a bad idea, especially if you're out before the sun really gets going. What you do need to watch for, though, is localized dense fog that was predicted for this morning. It might make visibility a bit iffy, and things can get slick real fast.
Foggy Mornings Ahead: If you're an early bird, be vigilant for patches of dense fog, which can reduce visibility and create slick spots on paths and roads. Drive or run with extra caution.
Trail Trouble Ahead
Now for the bad news, especially if you're a creature of habit with your routes. Construction and maintenance are hitting some of our favorite spots hard.
For instance, a significant stretch of Gravois Greenway, better known as Grant's Trail, is currently undergoing a major infrastructure project. They're replacing and repairing bridges between Officer Blake C. Snyder Memorial Park and I-55. This means that section of the trail is completely closed for roughly 90 days, with a hopeful reopening by early spring. If Grant's Trail is your go-to, check the detours at greatriversgreenway.org/gravois before you head out, or pick a different trail entirely. Nobody wants to hit a dead end halfway through a long run.
And it's not just Grant's Trail. Around town, you'll find other closures:
- Creve Coeur Park has gravel trail closures at Mallard Lake for maintenance.
- Dr. Edmund A. Babler Park has hazardous surfaces on its paved bicycle trail.
- Kinloch Park and Mitchell Park are both closed for construction.
- Forest Park also has ongoing Glade construction causing path closures and detours, particularly around Faulkner Drive and Forest Park Pkwy, expected to last until late 2026.
Widespread Trail Closures & Hazards: Several major parks, including sections of Grant's Trail and Forest Park, have significant closures or hazardous surfaces. Always check park and trail websites for current conditions and detours before you leave. Expect the unexpected and be ready to reroute.
Pollen Breakdown
Here's the lowdown on the sniffle situation:
| Pollen Type | Level |
|---|---|
| Tree | Low |
| Grass | Low |
| Ragweed | Low |
| Mold | Low |
So, while your lungs are doing great, your legs and wheels might have a tougher time navigating the city's current obstacle course. Plan smart, stay safe, and don't forget those layers.
Data grounded with National Weather Service, STLNature.org, MoDOT, and Great Rivers Greenway from February 25-26, 2026.