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 StoreTrolltunga — Troll's Tongue — is a horizontal rock ledge jutting 700 meters above Lake Ringedalsvatnet in the Norwegian fjord highlands above Odda. The approach hike of 22 to 27 kilometers and 900 meters of elevation gain makes it one of the most demanding day hikes in Norway, but the combination of the iconic ledge, the glacially carved lake below, and the dramatic fog that regularly fills the valley makes it one of the most compelling fog photography destinations in northern Europe. The fog here is not a softening element; it is an active, powerful presence.
The ledge itself is the primary photography location, and fog transforms it from an extraordinary rock formation into something almost mythological. When the valley fog fills to 700 meters and only the ledge and the upper rock face emerge, the sensation of floating above a cloud sea is complete. The approach trail offers multiple fog photography opportunities as you ascend through the inversion layer. June through September is the accessible season; late August and September are the most reliable for above-fog valley conditions combined with clear summit weather.
Trolltunga fog is fjord valley cold-air pooling fog. The Sørfjorden branch of the Hardangerfjord channels cold, moist maritime air into the valley below, and on calm nights following warm days, temperature inversions develop with fog filling to 500–800 meters while the ledge at around 1,100 meters sits above in clear air. Monitor weather at Odda valley level and at the ridge — a temperature difference of more than 8°C between valley and summit, with calm winds and valley humidity above 90%, gives a strong probability of above-fog conditions at Trolltunga.