Tim Kizirian on Hiking Mount Tamalpais in August’s Famous Fog

By Daniel Carter — Northern California Outdoors & Lifestyle Writer

On an August morning in Marin, the air carries that peculiar blend of eucalyptus, sea salt, and chill that instantly signals summer along the coast. For most people, summer means heat and sunshine. But for hikers on Mount Tamalpais, the season belongs to a different character altogether: Karl the Fog.

Locals speak of Karl like an old friend, a mischievous spirit that drifts in from the Pacific, swallowing hillsides and revealing them again in a breath. I recently sat down with Chico-based professor and hiker Tim Kizirian, who makes a point of climbing Mt. Tam every August to greet Karl in person.

“When you grow up in the valley, August means relentless sun,” Tim told me, warming his hands around a mug of coffee in Mill Valley before our hike. “But up here, August means fog. And it’s beautiful. You never know what you’ll see—or what you won’t.”

The Ritual of the Fog

For Tim, the annual hike is more than exercise; it’s a ritual of contrasts. He leaves Chico, where August temperatures climb past 100 degrees, and within hours finds himself layering jackets at a Marin trailhead. The shift is so sharp it feels like stepping between worlds.

“The first time I did it, I couldn’t believe how different it felt,” he said. “In Chico you’re hiding from the sun. On Tam, you’re chasing the fog.”

Karl has a way of toying with hikers. At one turn, a trail may be socked in, the trees dripping with condensation. Minutes later, the fog thins and suddenly the Bay spreads out in radiant sun. Then Karl returns, erasing everything again in silver-white haze.

“You don’t just see the fog—you feel it, taste it,” Tim explained. “It’s alive.”

The Routes and the Reveal

Mount Tamalpais offers dozens of routes to climb into Karl’s domain, but Tim favors the Dipsea-Steep Ravine-Matt Davis loop.

“You start under redwoods, where the fog feels like rain dripping from branches,” he said. “Then you climb up Steep Ravine with its ladders and switchbacks, and when you hit the meadows near Pantoll, suddenly you’re in sunlight. But it never lasts. Karl finds you again.”

That unpredictability is part of the joy. Unlike Chico hikes, which demand preparation for blazing sun and dry trails, Marin hikes in August demand flexibility. Rain jackets come off and on, hats are swapped for hoodies, sunglasses disappear into packs.

“The best moment,” Tim said, “is when you reach the crest and the fog breaks for just a minute. You look down, and the whole Golden Gate is there, peeking through waves of cloud. You feel like you’ve discovered a secret only Karl wanted you to see.”

The Culture of Karl

Fog in Marin isn’t just weather—it’s part of the culture. Locals named it Karl years ago, giving personality to a natural phenomenon that dominates summer life. On social media, Karl even has his own voice, tweeting sardonic observations as he drapes San Francisco and Marin in his gray shroud.

Tim laughs at the personification, but admits it captures the truth. “Karl really does have moods,” he said. “Sometimes playful, sometimes heavy. You can hike the same trail three days in a row and it’s a completely different experience depending on Karl.”

The fog shapes everything: the way plants grow, the way the air smells, even the way people pace their days. Where Chicoans adjust their rhythms to endure heat, Marinites move in step with Karl’s arrival and retreat.

Why August?

Though Karl visits throughout the summer, August is his prime. Inland heat pulls more fog through the Golden Gate, sending it billowing over Marin’s ridges in grand, cinematic displays.

“That’s why I come in August,” Tim said. “If you want to meet Karl in full form, this is the time. The fog is dramatic, sweeping, powerful. It makes Mt. Tam feel alive in a way you can’t capture in photos.”

Lessons in Contrast

Talking with Tim, I was struck again by the theme of contrasts. Chico’s August heat demands resilience and early mornings. Marin’s August fog demands patience and flexibility. One landscape burns, the other chills. Yet both require respect—and both reward those who step outside anyway.

“I love that I can live in both worlds,” Tim said as we stood on a ridge, Karl drifting past in slow currents. “Chico toughens you, but Marin softens you. You need both.”

The fog rolled back in then, blanketing the trail, muting the world to a quiet hum. Somewhere below, the Pacific churned unseen. Karl had the last word, as always.

And for Tim, that was the point. “It’s not about conquering the mountain,” he said. “It’s about meeting Karl.”

Daniel Carter writes about the outdoors and culture of Northern California, following the stories that connect weather, place, and the people who live in between.