Support

Evaporative cooling only works when the air can absorb more moisture. When humidity is high (usually above 70%), the air is nearly saturated and has nowhere to absorb the water you spray. The wet-bulb temperature limits how cold the air can become, and this formula (Stull 2011) is peer-reviewed and widely used in climate science.

The app estimates ranges, not exact values, because real-world cooling depends on wind, sun angle, surface wetness, and how long water stays on the ground—all variables at your site. The model is calibrated against published field measurements of uchimizu (traditional Japanese street sprinkling). On 33°C/55% humidity with a 2.5 m/s breeze and clear sun, the model predicts −0.1 to −0.5°C cooling, matching the 2008 Kano et al. field study.

Location is used only to fetch current weather from Open-Meteo. The coordinates are rounded to approximately 1 km precision and are not stored, saved, or linked to any account or identifier. No location history is kept.