True Wind Pro vs -40 Weather

True Wind Pro is a precise nautical wind calculator and training tool designed for sailors, navigators, and marine students. Convert apparent wind into true wind direction and speed using the classic nautical-school vector method — clearly visualized and easy to understand. Key Features • True wind direction (TWD) and speed (TWS) calculation • Apparent wind (AWA / AWS) support • Atmospheric pressure readings using the iPhone’s built-in barometer sensor • Pressure history with date and time • Easy access to pressure, wind direction, and wind force values for entering into the ship’s deck logbook on the bridge • Interactive radar and wind triangle plot • Step-by-step vector construction (nautical-school method) • Reverse calculator: find heading for a target apparent wind angle • Beaufort scale interpretation • Clean, distraction-free interface optimized for marine use Designed for Learning & Practice True Wind Pro doesn’t just give you numbers — it shows how the result is constructed. Perfect for sailing schools, exam preparation, and real-world navigation planning. The app also helps with practical bridge routines by making atmospheric pressure, wind direction, and wind force easy to check and enter into the ship’s deck logbook. Free & Pro You can perform 5 free calculations to try the app. Unlock True Wind Pro – Lifetime to get unlimited calculations forever with a one-time purchase. No subscriptions. No ads. Ideal for sailors, skippers, students, navigators, and anyone who wants to truly understand wind mechanics at sea.

-40 is the one temperature where Celsius and Fahrenheit are exactly equal. It is also a weather app that shows you both scales at once, so you never have to convert, with radar built the way the professionals build it. BOTH SCALES, ALWAYS Every temperature appears in °C and °F side by side. Choose which one leads in Settings. RADAR THAT RUNS ON YOUR PHONE Most weather apps show you radar. -40 Weather runs it. Instead of downloading finished pictures of the weather, the app downloads compact radar data built from NOAA measurements and draws the map on your device. Pan and zoom instantly, watch a smooth animated loop, and see where storms are heading next. Storm tracks, warning areas and storm reports are layered on top, and you can zoom in for high-resolution detail. Covers the United States and Canada. YOUR CITIES, ONE SWIPE APART Save as many places as you like and swipe between them. Add your current location or search for any city in the world. FORECASTS AT A GLANCE Current conditions, feels-like, highs and lows, a 7-day forecast, hourly detail, wind, precipitation, and sun and moon times. First light and last light show the usable daylight before sunrise and after sunset. Morning, midday and evening cards suggest what the weather feels like, from sweater weather to beach weather. ONE TAP TO THE DETAILS Tiles on the home page show live values and open hourly, precipitation, wind, moon, air quality and pollen, and the Field Guide. WEATHER ALERTS See active alerts from the National Weather Service right on the main screen, with optional notifications. AIR QUALITY AND POLLEN Check air quality and a 5-day pollen forecast covering tree, grass and weed pollen. ON THE WATER Marine conditions, tides, and estimated fishing windows for coastal and inland waters near you. These are estimates and are not for navigation. BUILT TO SIP YOUR BATTERY Location uses a coarse fix instead of constant GPS tracking, and weather alerts arrive by push instead of the app checking in on a timer. DYNAMIC ISLAND AND LIVE ACTIVITIES Optionally keep the current temperature on your Lock Screen and in the Dynamic Island. MADE YOUR WAY Pick a color theme, including one that shifts with the temperature, and choose metric or imperial units. The bottom bar uses Liquid Glass on iOS 26. Works on iPhone and iPad. Weather data comes from OpenWeather, the National Weather Service and NOAA, Open-Meteo, Google and other sources listed in Settings. Forecasts and alerts are for general information and are not a substitute for official warnings.