Ice Gauge: Ice Thickness

Ice Gauge estimates how lake ice grows over a winter, using the classic freezing-degree-day model and public air temperature data. It is a planning companion for your own measurements, not a replacement for them. Estimates are not measurements. Ice is never uniformly safe. Always drill and check. HOW IT WORKS • Pick a lake or river by searching or by dropping a pin on the map. • Ice Gauge loads daily mean air temperatures for the winter from Open-Meteo and adds up freezing degree days from the freeze-up date, which it detects automatically or you set yourself. • Thickness follows the Stefan relation h = α·√FDD, with growth coefficients from published ice engineering references. The result is shown as a range from heavy snow cover to bare, windswept ice. SEE THE ICE SHEET • A cross-section of the ice sheet grows downward beside a depth ruler. • A growth chart runs from freeze-up to seven days ahead, with the forecast span marked. • Slide through the season to see any day, or jump to the deepest point of the winter. CALIBRATE WITH YOUR AUGER • Enter the clear and white ice you measured. Ice Gauge refits the growth coefficient for that lake, so the curve follows your own water. • Your latest measurement is shown on its own, next to a reminder to follow your local authority's guidance. THAW AWARENESS • Thawing degree days are tracked separately. When a warm spell has arrived or is in the forecast, a "deterioration likely" notice appears. BUILT TO WORK ON THE ICE • Temperatures are saved on the device, so the app keeps working with no signal. • Metric or imperial units, Dark Mode and Dynamic Type. • An example lake with archived 2025–26 temperatures shows how it all works from the first launch. PRIVATE BY DESIGN No account, no ads, no analytics. Lakes and readings stay on your iPhone. Ice Gauge gives no verdicts about walking, driving or any load on the ice. Conditions change across a single lake: currents, springs, inflows and pressure ridges are invisible to any temperature model. Weather data by Open-Meteo.com, licensed under CC BY 4.0.