Every dew point app asks you to type in a temperature and a humidity, then does arithmetic you could do on paper. DewCast measures instead. Your phone carries a barometer. DewCast reads the actual pressure where you are standing, works out how far you sit above or below the forecast point, and corrects tonight's temperature and dew point curves for your real altitude. ONE TIME, NOT A NUMBER TABLE - Open the app: "Dew likely around 02:40" - or "No dew expected tonight" - A chart of tonight: air, dew point, and surface temperature lines - Below freezing, dew becomes frost - DewCast says which THREE SURFACES, ONE TAP - Attic, car camping, lens - each cools differently after sunset - Switch presets and the crossing recalculates instantly HONEST ABOUT ITS SOURCES - Pressure: measured on the device, with manual calibration - Temperature and humidity: local forecast for your coordinates - No forecast reachable? It says so, instead of guessing Keep a log of your checks: where, which surface, what the night did. Estimates are a guide, not a guarantee. No account, no subscription. One purchase, everything included.