Some days you can't tell from the window whether the mountain is visible or that's just bright gray sky.

Mountain Visibility Forecast is an independent app made by MileCheck LLC. It is not a government app and does not represent NOAA, the National Weather Service, USGS, MET Norway, the National Park Service, the FAA, or any other agency.

Open this and it says one thing: VISIBLE, PARTLY, or HIDDEN. Under that, the reason. Cloud height over you, whether the summit is in cloud, how far you can see, whether wildfire smoke has drifted in.

Eight mountains. Mount Rainier and the Olympics from Seattle, Mount Hood and Mount St. Helens from Portland, Mount Baker from Vancouver and Bellingham, Denali from Talkeetna, Mount Angeles from Port Angeles and the Strait, and Mount Baldy from Los Angeles. The app picks the nearest, or you pick.

The answer is computed, not collected. It reads aviation weather from the airports along your line of sight to the summit, and the cloud layers at the summit itself from the MET Norway model.

It tells you about the next five days, not just this minute. Hourly at first, then in six-hour steps.

You pay once. No subscription, no ads, nothing to unlock later. It collects nothing about you.

Where you are changes the answer, so that is built in. A Tacoma reading uses Tacoma's own overhead cloud and its 42-mile sightline, not Seattle's 60. On the morning you're the one clouded in, it tells you who isn't: "Visible from Tacoma, 26 miles off."

WHAT'S IN IT

Now. The verdict for your part of the region, with the reason underneath. Fifty-three regions across the eight mountains.

Forecast. The next five days, daylight hours.

Glow. Every upcoming sunrise and sunset, graded. It splits cloud by height, because a low deck hides the mountain and high cloud catches the color. When the summit is in cloud, the grade is Skip.

Spots. Viewpoints for each mountain, each with the reading from its nearest stations, sorted by distance from you, tap for directions.

Moon. Its phase every day, and on a clear night how long it stays up.

Volcano status. The current USGS alert level for Rainier, Hood, Baker and St. Helens.

After dark it tells you when first light is.

Notifications are optional and rare, never at night. There is no account.

CAMERAS

Rainier, the Olympics, Mount Angeles, St. Helens and Denali have webcam images on the Now screen. They come from the National Park Service and the USGS Cascades Volcano Observatory. Denali's is an FAA weather camera that the National Park Service serves. Each links to its source. Hood has three ODOT road cameras and Baldy a Caltrans camera. Baker has none yet.

WHAT IT ISN'T

This is a forecast. It reads instruments and models and gives you a read of the sky between you and the mountain, and some days it will be wrong. Denali is the hardest of the eight: airport instruments stop measuring cloud around 12,000 feet, and the summit is 20,310. Above that line the app is reading a model, and it says so.

PRIVACY

One thing leaves your phone: a push token, so a notification can find you. It is not linked to you and it is not used to track you. If you tap "Use my location," your location is used on the phone to pick the mountain and the region, and never leaves it.

SOURCES

Aviation weather from the NOAA Aviation Weather Center, including NAV CANADA stations.
https://aviationweather.gov/

Forecast from MET Norway (CC BY 4.0).
https://www.met.no/en

Wildfire smoke from National Weather Service air quality guidance.
https://airquality.weather.gov/

Volcano alert levels from the USGS Volcano Hazards Program.
https://www.usgs.gov/programs/VHP

Terrain from the USGS 3D Elevation Program.
https://www.usgs.gov/3d-elevation-program

Webcams from the National Park Service (https://www.nps.gov/) and the USGS Cascades Volcano Observatory (https://www.usgs.gov/observatories/cvo).