What the app shows you
Full FogCast score, fog type, chase-or-skip verdict, and 10-day outlook — all in the app.
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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 StoreFranconia Notch is a narrow mountain pass in the White Mountains of New Hampshire, flanked by the Franconia Ridge on the east and the Kinsman Ridge on the west, with Echo Lake and Profile Lake on the valley floor. The notch funnels cold air drainage from both ridgelines, and the combination of enclosed valley, bodies of water, and high surrounding terrain makes it one of the most reliable radiation fog locations in northern New England. Morning fog on Echo Lake with the ridgelines emerging above is a classic White Mountains photograph.
Profile Lake — the former reflecting pool below the now-collapsed Old Man of the Mountain — and the notch floor near Flume Gorge are the best fog photography positions at ground level. The Cannon Mountain aerial tramway gives access to above-fog views when conditions are right, with the notch and surrounding terrain visible below the cloud layer. Autumn foliage season, mid-September through mid-October, combined with valley fog produces exceptional color-and-mist photography. The fog season extends through November and into winter.
Franconia Notch fog follows the classic New England pattern: clear autumn nights after the passage of a high-pressure system, light winds, and moisture from the surrounding forest and lakes. If overnight temperatures are forecast to drop to 5°C or below with calm winds and dew point within 3°C, fog in the notch by 5 to 6am is very likely. The narrow valley geometry means fog can be extremely dense even when surrounding terrain is clear.