Thermodo's miniscule thermometer dongle is fun and useful

Thermodo Thermometer dongle for iOS

Over the past week I've had the opportunity to play with some fun little devices that let you quantify your surroundings. First, there was the Blue Maestro Tempo, a Bluetooth-enabled temperature-sensing device provides your favorite iOS device with temperature info. As I note in my review, it's accurate, but not exactly portable. Next was the WeatherFlow Wind Meter, a smartly-designed app-enabled anemometer that gives you an idea of how fast the wind is blowing. Now I'm looking at Thermodo, a really small app-enabled thermometer that plugs into the headphone port of your iDevice and communicates with an iOS app to give you an idea of the temperature near your iPhone or iPad.

The basic black Thermodo is quite affordable for anyone who loves the outdoors, with a price tag of just US$29.99. An "anodized aluminium" version is available for $44.99, and is something that Jony Ive would probably be proud of.


Thermodo is tiny -- just 0.4 inches in diameter and 1.4 inches long, weighing 0.2 ounces. That's with the keychain attachment; the actual device only projects out of your headphone port by about .4 inches. If you read my review of Tempo, you probably remember me talking about Ron, a friend who wants a small thermometer that works with his iPhone. Thermodo is exactly the device he was dreaming of, something he can clip onto a keychain and use when he wants a fairly accurate reading of temperature -- anywhere.

To get the device working you just download the company's free accompanying universal iOS app and launch it. Your first indication that this might be a somewhat temperamental device comes with the series of startup screens that warn you that heat from your hand or iOS device may throw your temperature reading out of whack:

Fortunately for me, I have two other devices in my office that I can use to check the temperature and they're both pretty well in sync -- one is the Netatmo Personal Weather Station, while the other is the recently reviewed Tempo.

When I just turned on the Thermodo and started tracking the temperature, it showed the room that I am in at a balmy 70.4°F, climbing up to 72°F in a couple of minutes before settling at that level. The Tempo showed a constant 66.2°F, while the Netatmo stayed at a 67.1°F. So there wasn't too much of a discrepancy in the readings, although if I held the iPhone 5s and Thermodo in my hand, it started raising the temperature almost immediately.

Fortunately, there are Thermodo settings you can use to compensate for the heat that your device and body put off. Turning on the compensation with a "regular" setting, the temperature was in sync with the Netatmo at 67.1°F. Pick up the phone, however, and the temperature started climbing again.

Thermodo and iPhone 5s

The Thermodo product FAQs show that the developers are well aware of the need to keep the thermocouple in the device away from heat sources, as they recommend using an audio extension cable to insure an accurate reading. I found that if I just launched the app with compensation turned on and set the device down for a few minutes, it was pretty accurate but gradually drifted up out of range of the other devices. Using an extension cable, the Thermodo stayed at a fairly constant temperature.

For weather geeks, outdoor enthusiasts, and iOS fans who want to prove to their significant others that it is really too hot/cold right now, Thermodo's just the ticket.