Meet Tempy: a wireless cloud-connected sensor that sends live temperature, humidity, and air pressure data to you phone, tablet, and PC. These sensors have up to 10 years battery life. They are waterproof, so you can use them in any environment.
Tempy can detect temperatures between -40 to 140F. They also sense humidity from 0% to 100% with +/- 3% accuracy. The wireless range is up to 4000 ft.