Digital pool thermometers are the best way to tell what the temperature is of your swimming pool. I know it sounds pretty obvious but so you know, not all pool thermometers are the same. In fact there are two different categories of thermometers such as digital and your standard mercury ones. Also for a swimming pool you can have a floating or handheld one.
We would like to recommend you get a nice digital handheld or floating thermometer to read the temperature in your swimming pool. The reason is that mercury filled floating thermometers can get damaged from being in your swimming pool from either the weather or swimmers. The problems with these types is that if they break you could have a real mess on your hands including mercury in the water and broken plastic and glass that could rip the liner or even worse, hurt a swimmer. If you do decide to get a floating thermometer then make sure that you tie it to one place in your swimming pool so that it doesn’t just freely float around. Most people like to tie their thermometers to the ladder.
With that said, here are the top 5 digital pool thermometers that we recommend for your swimming pool:
HydroTools Digital Floating Thermometer
Easy to read Fahrenheit/Celsius LCD thermometer with nylon cord.
Sears

Ace® Solar Power Floating Pool Thermometer
Professional grade. Solar power with battery back-up and digital display. Complete with string. Displays Fahrenheit or Celsius temperature range 0- 50C or 32-122F
Ace Hardware

P3 International Wireless Pool Thermometer and Display
High tech wireless pool thermometer for monitoring pond water temperature and more! Accurate measurement of pond water temperature is essential for proper seasonal nutrition for your prized koi. The Wireless Sensor and Display Set helps simplify this task. Floating thermometer with built-in digital display transmits temperature data to the indoor temperature display station. Sensor range of up to 300 feet allows flexible placement of the temperature display station within your home. Audio and visual alarm alerts you if temperature is not within your defined range. Convenient frost warning feature activates when pond water temperatures drops below 39.2 degrees Fahrenheit.
Foster And Smith's Aquatics

Tell-All ™ TempRecorder Digital Pool Thermometer
The Tell-All is a digital thermometer for spas and swimming pools with calendar and clock. The thermometer logs up to 100 days of data. Displays temperatures, highs and lows on graphs. The unit comes in it's own clear waterproof case for when submersing into the water.
PoolSupplies.com

Hanna Portable Electronic Thermometer
Hand-held quick-dip electronic thermometer is ideal for spas! A digital pool thermometer is easy to read and accurately displays the water temperature in one second! Includes battery and protective cap.
In The Swim




