I'm an S.F. Chronicle meteorologist. Here's my favorite weather app

The most common question I get as a meteorologist in San Francisco isn't about the forecast. It's also not about an unidentified cloud, or whether it's jacket weather. People always want to know what weather apps I use.

Until recently, my answer had been, "I don't use apps." That changed this year.

A slew of apps are now in my daily rotation, my favorite being "Foggy," a hyperlocal project developed by a couple who were both former Strava executives and released earlier this summer. The app is designed for people in San Francisco - and other Bay Area cities - to track and report the region's infamous fog in real time.

Upon opening the app, which costs $5.99 on Google Play and the Apple App Store, users can toggle between 2-hour and 24-hour loops of satellite imagery, similar to the Chronicle fog tracker .

The most innovative aspect of Foggy is the anonymous reports from across the city.

Users can pick from 22 words to describe conditions at their current location. Adjectives vary from the thickness, speed and position of cloud cover and include phrases like, "moving in,"  "burning off," "bright," and "stormy". "At the fog line" is another option, after a request from a user in the Panhandle.

I use Foggy the most to see if the fog pattern is unusual. If the number of reports is higher than usual, it may indicate a particularly low or wet fog. The app also helps me avoid the fog when I'm trying to photograph a colorful sunset.

Foggy co-founder Michael Horvath's inspiration began when he moved to the Outer Sunset in 2019.

"All of a sudden I was living in the fog a lot, and wasn't really happy about it," he said.

Two years later, Horvath discovered Fog Today , a website for tracking the fog via satellite imagery, and "I went from being frustrated with the fog to really appreciating it."

Horvath eventually reached out to Logan Williams, the developer of Fog Today, who he recruited to help create Foggy, along with six others. The app was released just in time for San Francisco's Fourth of July fireworks show to be swallowed by fog .

While satellite imagery can show the spatial distribution of clouds from high above, reports below, within or outside the fog add a sense of feel to its progression.

"Fog is not one thing," Horvath said. "It's a three letter word, but it has so much depth to it. It'll take your breath away when you see it off a little bit in the distance. And then when you're in it, it's like, 'where is the fog? ' It's all around you. You never quite figure it out."

Though most of its reports are from San Francisco, users sometimes write in from Marin, Berkeley or other cities.

Since Foggy was launched June 29, an average of 250 reports are submitted on the app each week (most of them are on weekends). The Fourth of July, San Francisco Marathon, Outside Lands and other special events attract higher numbers of users. The app particularly attracts photographers, gardeners, pilots, hikers and surfers, co-founder MacBeth Horvath said.

"During the foggy season we're hearing it's helping some people who need that break to know how far they have to go to get the sun," MacBeth Horvath said. "You know, vitamin D is important and helps us in our moods."

Even walks on San Francisco's Ocean Beach, like I did with the Horvaths on a recent cloudy summer day, can benefit from an easy way to track the fog.

"We might get a clearing, by the way the fog is moving," Michael Horvath said as he looked out at a sun-soaked Mount Tamalpais and compared the satellite view on his app.

By the time we left the beach an hour later, the sun began to poke out from behind the persistent clouds.

Other apps

I'm typically cautious of weather apps because the forecasts are automated or they're flooded with advertisements with no way of paying for an ad-free version.

Unlike other free weather apps, "Everything Weather," which was released in early 2025, pulls data exclusively from the National Weather Service and doesn't run ads. Forecasts are altered by meteorologists, and users can easily access in-depth weather discussions, warnings, radar, satellite and almanac data without having to dig around various sources.

"Everything Wx," as it's dubbed, was developed by Cory Mottice, a warning coordination meteorologist at the National Weather Service in Corpus Christi, Texas, who built the app in his free time. Marshall Shephard, a professor of meteorology at the University of Georgia, reviewed the app in Forbes last year.

California Smoke Spotter is another free app that is excellent for tracking wildfires and air quality, and can help answer the question of "where is this smoke coming from?"

The app was created by the California Air Resources Board in 2021, although I just learned of it earlier this year. It helped calm nerves earlier this week when smoke from controlled burns in Marin County drifted over San Francisco Bay.

Another app I recommend is " Atmos for Weather and Photo " built by Bay Area photographer Matthew Raifman. The app features photography conditions on a 0 to 100 scale based on hourly weather and includes an algorithm for scoring sunset forecasts. Data for astrophotography is also available. Atmos is free for two weeks and then is $3.99 per month, or $29.99 per year.

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This article originally published at I'm an S.F. Chronicle meteorologist. Here's my favorite weather app .