FogCast · Mount Washington, NH
Fog Forecast for Mount Washington
Know before you drive: FogCast checks the conditions that produce photogenic fog
Reading current conditions…
🔒 App Exclusive
The full FogCast forecast is in the app.
Get more than a snapshot of current conditions. The LightCast app unlocks everything to plan ahead
- 📈 Full FogCast score (0–100)
- 📅 7-day fog outlook
- 🌅 Best photography windows
- 🔔 Push alerts when conditions improve
- ⭐ Save favorite locations
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7-day free trial · $2.99/mo
Why fog is hard to predict
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.
Dew Point Depression
When air temperature and dew point converge below 2°C, the air is near saturation. This is the single strongest fog predictor and the first thing FogCast checks.
Wind Speed
Fog needs calm air. Below 5 km/h is ideal. Above 15 km/h, fog disperses before it can pool in the valley. A standard weather app won't flag this combination.
Overnight Sky Clarity
Clear overnight skies let the ground cool rapidly, pushing surface temperatures toward the dew point. Counterintuitively, clouds overnight suppress radiation fog.
Temperature Trend
FogCast reads the overnight temperature arc. If temps are converging toward the dew point hour by hour, fog probability increases significantly by pre-dawn.
Check today's FogCast
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
Get notified instead of checking every morning
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.
⏰
Wake up only when conditions look promising
🚗
Avoid wasted drives when fog never forms
⭐
Save your favorite photography locations
🌫️
Never miss a rare dense fog event
Fog photography at Mount Washington
Mount Washington, at 1,917 meters the highest peak in the northeastern US, holds the record for the highest wind speed ever recorded by a surface weather station and is in cloud or fog on over 300 days per year. The summit sits at the convergence of three major storm tracks, and the resulting frequency of cloud immersion, rime ice, and fog-laden winds makes it one of the most extreme and atmospheric mountain environments in the eastern US. In calmer conditions, the summit can be above a fog layer filling the Presidential Range valleys, creating sea-of-clouds views across the White Mountains.
The Auto Road and Cog Railway give non-hiking access to the summit, though photographers should be prepared for the summit to be completely socked in with no view at all — this is the more common outcome. The best above-fog conditions occur when a stable high-pressure system follows a frontal passage and the valley fog is trapped below 1,500 meters. The Appalachian Mountain Club huts on the ridge, particularly the Lakes of the Clouds Hut, offer overnight positions for catching the best morning cloud conditions on the upper mountain.
Weather on Mount Washington changes with extreme speed. Summit conditions bear almost no relationship to valley conditions. A clear valley day can mean a fog-shrouded summit, and vice versa. Check the Mount Washington Observatory's summit forecast directly — they provide specific cloud ceiling and visibility data that is far more useful for photography planning than any general forecast.
Other fog photography locations
Frequently asked
Can I check FogCast on the website?
This page shows a preview of current conditions, including humidity, wind, temperature, and dew point. The full FogCast score, 7-day outlook, push notifications, and best shooting windows are available exclusively in the LightCast app for iOS.
Is FogCast free?
The current conditions preview on this page is free, no account needed. The full FogCast tool is in the LightCast Suite iOS app, which includes a 7-day free trial. After the trial it's $2.99/month, cancel anytime in the App Store.
Why use FogCast instead of checking humidity?
Humidity alone doesn't tell you whether photogenic fog is likely. High humidity with strong wind produces no fog at all. FogCast combines dew point depression, wind speed, overnight sky clarity, temperature trend, and visibility into a single score built specifically for fog photography planning.
What is FogCast's scoring scale?
FogCast scores fog conditions from 0 to 100. A score of 75 or above indicates dense fog is expected. 55 to 74 means fog is likely and worth chasing. 35 to 54 suggests patchy mist is possible. Below 35, conditions are unlikely to produce photogenic fog. The full score is available in the LightCast app.
