There are lots of iPhone apps which will tell you the weather in your general area, but if you want to know the precise weather at a specific location — such as at your house — you need a thermometer. According to the fine contributors to Wikipedia, the thermometer can be traced back to Hero of Alexandria, a mathematician and engineer who lived from 10 AD to 70 AD. But Apple's HomeKit technology wasn't around back then, so the folks in Alexandria couldn't use an iPhone to check the weather at their house. Back in 2015, I reviewed a device made by Elgato called the Eve Weather. The Eve Degree is the second generation of that device; you can still find the Eve Weather on Amazon, but Elgato no longer has it listed as a product on its website. Elgato sent me a free review unit of the Eve Degree, and I've been trying it out for the last few weeks.
The hardware
The Eve Degree is a small 2.1" x 2.1" square which is 0.6" deep, a much smaller size than the Eve Weather, which was 3.1" x 3.1" and 1.3" deep. The body is made of anodized aluminum, and the front is acrylic glass. It looks very nice.
Unlike the Eve Weather which just had a white plastic front, the front of the Eve Degree has an LCD display which displays the current weather. This is a great addition, making it simple to see the current temperature without even having to use your iPhone. The default setting of the Eve Degree is Celsius, but using the Eve app on an iPhone you can easily change that to Fahrenheit.
The back of the device has a hole, so you can hang the Eve Degree on a nail to mount it on a wall. There is also a reset button on the back, and a cover for a replaceable CR2450 battery. Elgato says that the battery should last about a year, and replacement batteries cost around $1 to $3 on Amazon, depending upon the brand and the quantity that you buy. (The Eve Weather used AA batteries which only lasted about three months.)
Etched into the bottom of the Eve Degree is a unique HomeKit code that you use when you first set up the device with your iPhone. It's nice that it is down there so that if you ever need to perform a setup again and you no longer have the box or instructions, you will still have that code. And having it etched looks much nicer than just putting a sticker down there.
The measurements
The Eve Degree measures three things: First, it monitors the weather, accurate to within 0.54° Fahrenheit. Second, it monitors the humidity, accurate to within 3%. Finally, it monitors the air pressure, accurate to within 1 mbar / 0.03 inHg. In the following picture, you can see the data after I moved my Eve Degree from my back porch to my study so that I could take a picture of it for this review. You can see that the humidity and temperature decreased noticeably after I brought the device inside.
The Eve Degree logs each of these measurements every 10 minutes, and can store up to two weeks of measurements on the device. The main page on the Eve app shows you about the last 12 hours, but you can get more information for the past hour/day/week/month, and can even see each specific measurement in the log.
Every time you use the Eve app to check the current measurements, that log is downloaded to your iPhone. Thus, as long as you use the Eve app to check in with the Eve Degree at least once every two weeks — or, to be safe, once a week — your iPhone will have an unlimited historical log of all of the measurements. Using the Eve app, you can even export this data to a spreadsheet.
Where to place the Eve Degree
The Eve Degree can work either indoors or outdoors. If you keep it outdoors, it is rated IPX3, so it is OK if it gets wet from rain, although it shouldn't go underwater or be sprayed with a jet of water.
Having said that, to get the most accurate readings, you should put it in a place that is always in the shade — which means that it probably won't be exposed to much rain either. Official outdoor temperature measurements are always in the shade because when a thermometer is in direct sunlight, the sun rays can heat up the fluid that is used to measure the temperature, so you end up getting a reading of that fluid and not the air. At my house, I put the Eve Degree on my back porch in a spot that was mostly shaded, but every morning there would be a short period of time when it was exposed to sunlight. Thus, when I looked at my temperature logs on sunny days, I saw artificial peaks that lasted about 30 minutes. For example, in the following picture, I got a recording of almost 110º the other day. It certainly can feel pretty darn hot in New Orleans in the Summer, but not that hot.
If you don't want those false readings, move the Eve Degree to a place that will not get direct sunlight.
One other issue to think about for placement is keeping it near a HomeKit hub. The Eve Degree uses Bluetooth 4.0 to send data. So if your iPhone is reasonably close by, you can get data measurements. But if your iPhone is far enough away from the Eve Degree — either on the same house or when you are away from home — the only way that you can see the current temperature is if your Eve Degree is in relatively close proximity to a HomeKit hub device. You also need to use a hub if you want to use the Eve Degree to do automated tasks (more on that below). If you have an Apple TV, that will work, so I place my Eve Degree on my back porch in a location that is just on the other side of the wall from where my Apple TV is located. An iPad can also serve as a HomeKit hub, if you keep it at your house all of the time, and a HomePod can also serve as a hub. See this page on the Apple's website for more details.
Unfortunately, if the place at your home that you have decided to keep Eve Degree to take measurements is not sufficiently close to a HomeKit hub, then you lose some of these more advanced functions. As a workaround, you could use a Bluetooth range extender to act as a bridge between the Eve Degree and your HomeKit hub. Except that these products don't exist yet. Elgato announced one called the Eve Extend back in January 2017, but it still isn't available. When someone recently asked Elgato about this on Twitter, the company said that it has "nothing to announce at this point" and Elgato seemed to point the finger at Apple:
We have nothing to announce at this point. What's more, please note that the range extender category currently isn't listed on the Apple Support page with upcoming and available Home accessories: https://t.co/PfOlZ7JNy3
— Elgato (@elgato) May 30, 2018
Siri and automation
Because the Eve Degree is a HomeKit device, you can use Siri with it. Thus, instead of opening up the Eve app, you can just ask Siri the current temperature at your house or your backyard.
You can also set up HomeKit automations, such as turning a fan on or off depending upon the temperature, or turning on a lamp when it gets really hot outside. With the new Shortcuts feature in iOS 12 coming this Fall, I suspect that you will be able to do even more sophisticated things with HomeKit automation.
Durability
Everything about the Eve Degree seems like a much better design than the Eve Weather. However, one thing that I don't know about is long-term durability. I used an Eve Weather on my back porch for about two years, and then it stopped working completely. I haven't seen other people complaining on the Internet about similar problems with the Eve Weather, so maybe there was just a problem with my unit. Perhaps it was exposed to too much water in a very strong rainstorm.
Whatever it was that caused my Eve Weather to bite the dust after two years, hopefully this Eve Degree will work for even longer.
Conclusion
Only you can decide if you have an interest in measuring the precise weather at your house. Perhaps you want the specific temperature right now. Perhaps you want to see a historical log. Or perhaps you want to trigger some HomeKit automation based upon the weather. For the two years that I used an Eve Weather, it was interesting to have access to that data, and while I cannot say that it was life-changing, I liked the product.
If you do think that this sort of product is for you, the Eve Degree works very well. I love that you can see the temperature right on the device itself, and I like the smaller size and the aluminum body. And I like that you don't have to change the battery every few months. It is also nice that HomeKit has improved over the years — triggers were not even possible when I first started using an Eve Weather — and with the increased automation coming in iOS 12 with Shortcuts, I expect that this will only improve.
It is a shame that you need to keep an Eve Degree reasonably close to a HomeKit hub to get the full value out of the product, but depending upon the layout of your house, this might not be a problem at all. And perhaps even that will improve the in future if and when Elgato releases the Eve Extend.
