The recipe-and-weather conversion
This is the single most-searched unit conversion on the web. The two go-to reference points to memorise: 0°C = 32°F (water freezes) and 100°C = 212°F (water boils). Practical anchors — 20°C = 68°F (room temperature), 37°C = 98.6°F (body temperature), 180°C = 356°F (moderate oven), 200°C = 392°F (roasting oven). Weather apps default to °F only in the US, Cayman Islands, Bahamas, Belize, Palau, and a handful of others — everywhere else, °C.