Casio has officially brought its popular SAN100 “Sauna Watch” to the United States, giving wellness fans and sauna regulars a purpose-built timepiece that’s made to handle the heat. First revealed in Japan in late 2024, the watch started as a crowdfunded product before expanding to a wider release there in September 2025. Now, it’s finally available for US buyers as well.
Known in Japan as the “Sadokei,” the Casio SAN100 comes in two models: the SAN100H-1B and the SAN100H-7B. As the name suggests, these watches are designed specifically for sauna use, with a heat- and humidity-resistant build intended to withstand temperatures up to 100°C (212°F) and high humidity for about 15 minutes. It also offers 50-meter water resistance, making it suitable for everyday wear beyond the sauna.
Power is another highlight. Casio says the SAN100 uses a heat-resistant BR1225A battery rated for up to five years of runtime, which is especially appealing for anyone who wants a simple, reliable watch without frequent battery changes.
In terms of size and comfort, the SAN100 is compact and lightweight, measuring 40.2 x 35.4 x 12.9 mm (about 1.58 x 1.39 x 0.51 inches) and weighing just 25 g (around 0.88 oz). It features an analog display with two hands and clear Arabic numerals for easy reading at a glance—ideal when you’re trying to keep tabs on time in a steamy environment.
The watch uses a non-metallic resin case and includes two buttons: a mode button on the top left that lets you switch between Standard Time Mode and Sauna Mode, and a reset button on the top right. Sauna Mode includes a 12-minute counter, reflecting a traditional timing approach commonly associated with Japanese sauna routines—often the recommended amount of time to spend in the sauna before cooling off.
One of the most distinctive design choices is the coil-style band. It’s similar to the stretchy coil bands used for locker keys, designed to be comfortable, secure, and easy to wear in a sauna setting.
Right now, US shoppers can purchase the black Casio Sauna Watch SAN100H-1B for $110 through Casio’s official online store. A second color option—white and orange (SAN100H-7B)—is expected to arrive in the US later, and it’s anticipated to carry the same $110 price point.
