Foggy | A New Way to See Where the Fog Is In San Francisco
Why do we need an app for fog?
Do I need a jacket? Is it going to be foggy? Where the heck is the sunshine today?
These questions are fundamental to life in the San Francisco Bay Area. Because fog is fundamental to life here.
Fog is part of the fabric of the environment, just like the iconic hills and bridges. And it is the key variable that determines whether your neighborhood — from the Mission District to Outer Sunset — feels awash in sunny splendor or is blanketed by moody mist.
If you start your day dressed for sun then get caught in the fog without a jacket, you remember forever.
The exceptional frequency of fog in the Bay Area (over 100 days each year) impacts the routines, recreation and attire choices of millions of residents and visitors. And while the Bay Area community is connected by fog, everyone relates to it differently.
Fog gives some residents permission to hunker down indoors for the day, while it calls others to pack an extra layer for their outdoor pursuits. Fog feels gloomy to some, while others feel relieved by the free air conditioning after a heat wave. It can frustrate poorly prepared, shivering Ocean Beach goers and it can inspire photographers chasing iconic images of the Golden Gate Bridge shrouded in natural atmospheric wonder.
In a place where tectonic plates collide and nature abuts technology’s cutting edge, there has never been a straightforward way to know in real-time where it’s foggy and where it isn’t.
This is why we’re building Foggy: to help our community easily understand where the fog is, and decide how to interact with it.
Knowledge is power, and your day just goes better when you’re fog aware.
Why is the Bay Area so foggy?
As summer’s warm air moves across the chilly Pacific Ocean water, it condenses into a thick blanket of misty clouds. This iconic coastal fog can make a summer day feel like the coldest winter you ever spent…
Meteorologists and academics have been studying fog for decades, but it remains mysterious in many ways. We’ll dig into the science behind fog in future posts, but this video created by KQED is a helpful explainer for anyone who is fog-curious.
Who are the people building the app for fog?
Foggy’s co-founders are San Francisco locals, outdoor enthusiasts and tech industry vets who understand the impact fog can have on your day, because they experience it themselves.
After stints leading large teams at global companies like Strava, Pinterest and Xbox, MacBeth and Michael Horvath have shifted gears, choosing to build technology on the neighborhood scale for the benefit of their local community.
When Michael moved to the Outer Sunset neighborhood in 2019, he was often bumping into fog during summer bike rides. These encounters with the fog were typically surprising, and thus mostly unpleasant. But that all changed when a friend introduced him to the website fog.today, an open-source website displaying NOAA satellite images of the Bay Area.
The ability to see the approximate location of clouds and fog on any given day was a game changer, and gave Michael the power to decide whether to go toward the fog, or away from it.
Right away, this additional information and agency to choose when and how to interact with the fog changed how he felt about it. He began to appreciate the fog’s benefits: the unique look and vibe it brings, the naturally cooling air conditioning it provides, and the way it sustains native plants and animals.
His partner MacBeth took note of the vibe shift, and how quickly an attitude can flip from negative to positive with just a little bit of useful information. It was clear to both of them that being “fog aware” and avoiding surprises makes it easier to embrace the wonder of fog.
MacBeth and Michael then reached out to Logan Williams, creator of fog.today in early 2025 to share their appreciation for his site and discuss how to build an even more user-friendly experience inspired by his original project. With their first advisor on board, they set out to build Foggy, an app for Bay Area fog and its community.
Is Foggy a weather app?
This is a question we get asked often, and one we ask ourselves too.
There are thousands of weather apps, but none reflect the complexity of San Francisco’s fog. We believe fog deserves its own dedicated experience, because it impacts where, when and what you decided to do on a given day.
Fog isn’t all or nothing; it comes and goes seemingly out of nowhere, and it can be hard to predict which neighborhoods it will choose to blanket. Fog is seen, and it’s also felt. How it looks from a satellite or through one particular window can differ widely from how it feels on the ground in a given microclimate.
That’s where the magic of Community Reporting comes into play. By combining satellite imagery with ground-level Community Reports, Foggy empowers neighbors to help each other understand real-time fog conditions.
Foggy is a new kind of weather app focused on how the rapidly changing atmospheric conditions impact our community – just don’t call it vaporware.
2 hour playback on Foggy
What’s next for Foggy?
Our team is charging ahead toward Foggy’s official app store debut in June, just in time for fog season.
Stay in the loop by signing up for the Foggy newsletter, and check back here for more blog posts where we share learnings from community feedback, new features we’re adding to Foggy, and deep dives where our engineers unpack the technical complexity that brings Foggy to life.
-The Foggy Team
