What the app shows you
Full FogCast score, fog type, chase-or-skip verdict, and 10-day outlook — all in the app.
Get LightCast Suite on iOS
Know before you drive: FogCast checks the conditions that produce photogenic fog
Get more than a snapshot of current conditions. The LightCast app unlocks everything to plan ahead
Humidity alone isn't enough. Wind alone isn't enough. Cloud cover alone isn't enough. Photogenic valley fog requires several conditions to line up at once, and most weather apps don't read them together.
Set a FogCast threshold once. The app will alert you when conditions at your saved locations look promising, so you're not manually checking at 4am.
Don't waste a sunrise drive. Check FogCast before you leave.
Download on the App StoreTelluride sits at 2,667 meters in a box canyon carved by the San Miguel River in the San Juan Mountains of southwestern Colorado. The canyon's three-sided enclosure — vertical walls rising 500 meters on three sides — creates an exceptional cold-air trap that produces some of the most persistent morning fog of any Colorado mountain town. In autumn, the combination of box canyon fog, aspen gold on the valley slopes, and the iconic Victorian mining town architecture creates photography that is distinctly unlike anywhere else in the Rockies.
Main Street Telluride and the city park at the east end of town are the primary fog photography locations — the street corridor lined with historic buildings and yellow cottonwoods in fog captures the 19th-century mining town atmosphere perfectly. The Bridal Veil Falls road above town looks back down into the fog-filled canyon with the town's rooflines barely visible. The gondola ascent to Mountain Village at 2,850 meters offers an above-fog perspective when the canyon is fully fogged in. October is the peak month; the box canyon traps cold air with exceptional efficiency and morning fog occurs on most clear, calm autumn nights.
Telluride fog is almost entirely canyon drainage fog. Cold air flows down from the surrounding peaks overnight and pools in the box canyon bottom. Because the canyon is enclosed on three sides, there is no exit for the cold air and it accumulates rapidly. By 3 to 4am on a calm, clear night in October, the entire canyon floor is typically at or below the dew point. Even light winds from the west can clear the fog quickly; completely calm conditions at sunset are the clearest predictor of dense canyon fog at dawn.