Aqara W100 Climate Sensor review: A great but unfinished piece for Matter

It’s been a while since Aqara unveiled the W100 Climate Sensor, a device designed to serve as both a thermostat control and display sensor for home climate systems. It caught my attention right away when it’s showcased in CES earlier this year.

In my two weeks’ using this device, I can barely let it go as it adds more convenience than I expected even though some features are missing for the Matter mode. But is it truly worth it? The answer depends on your needs. Here’s an unpacked review:

*The W100 supports both Zigbee and Matter-over-Thread. In this article, I’ll focus on the Matter and Matter-related aspects (bridged experience).

Aqara W100 Climate Sensor pros and cons

Pros:

• Clean design

• Long battery life

• Large display and buttons

• Flexible installation

• Dual-protocol support

• Stable connectivity

Cons:

• Loose buttons

• Major features missing in the Thread/Matter mode

Sleek and functional design

The W100 Climate Sensor has a sleek and white case design, typical of most Aqara products. This minimalist style makes it easy to blend into existing home setups. The sensor can be mounted with a nail or adhesive sticker hook, or you can fix the metal holder to the wall with screws, attaching the sensor magnetically. Be aware that the sensor has two SKUs with different accessories in the box; for the metal holder, you need the TH-S04D model, according to Aqara.

If you prefer to place it on a desk or tabletop, there’s also a kickstand that provides the perfect angle. Personally, I placed it on my desk to easily adjust the air conditioner installed in my bedroom.

The W100 offers a useful combination: climate sensors and scene buttons, assembled like a classic thermostat controller, even though it’s not displayed as such in the Matter ecosystem.

The device features a large display showing temperature and relative humidity (RH) from two sources, as well as thermostat status with three buttons to the side. I appreciate it that they make it larger and more accessible at a glance, the button size is also friendly to users with larger hands.

However, the button feedback is compromised – they feel quite loose and offer minimal tactile response. And the display could be less clear from certain perspectives.

W100 Climate Sensor's Matter mode

The device defaults to Matter mode, so you won’t need the Aqara app to set it up. I tested it with Apple Home, SmartThings, Alexa, Google Home, Home Assistant, and Aqara Home.

The first thing I noticed is its limitation of five “fabrics” – essentially, it can only be added to five Matter apps or platforms (Apple typically occupies two slots). But it should be enough for most users. Here is an overview of its features on these Matter platforms:

• Apple Home: Configures two sensors and three buttons, with support for long, short, and double press triggers.

• Google Home: Displays all entities, but only humidity sensors can be used as routine triggers.

• Home Assistant: Supports all features, but using the buttons for automation requires extra effort. Here’s a demo code to trigger a thermostat:

alias: Aqara Thermostat Control Temp Plus
description: ""
triggers:
  - trigger: state
    entity_id:
      - event.climate_sensor_w100_button_3
conditions:
  - condition: or
    conditions:
      - condition: device
        device_id: 10e9f8d2029d02d54003ca9bcbce92e2
        domain: climate
        entity_id: 188c75396e9055d2d53783e182a8b7f2
        type: is_hvac_mode
        hvac_mode: cool
      - condition: device
        device_id: 10e9f8d2029d02d54003ca9bcbce92e2
        domain: climate
        entity_id: 188c75396e9055d2d53783e182a8b7f2
        type: is_hvac_mode
        hvac_mode: heat
    enabled: true
actions:
  - target:
      entity_id: climate.aqara_m3_hub
    data:
      temperature: |
        {{ state_attr('climate.aqara_m3_hub', 'temperature') | float + 1 }}
    action: climate.set_temperature
mode: single

• Alexa: Only one button is supported for routines, but sensor readings can be used as triggers.

• Aqara: Temperature and humidity readings, along with three programmable buttons, are exposed, available to trigger automations.

To my surprise, the device was responsive, and I had no issues setting it up. It remained stable throughout my two-week testing period. I typically use Matter devices across two platforms simultaneously, and the W100 didn’t exhibit any unresponsiveness.

However, as mentioned earlier, the W100 doesn't appear as a thermostat controller in Matter platforms, nor can it be paired with a Matter thermostat or air conditioner as Eve’s products do. Currently, the Thread mode feels unfinished – it doesn’t utilize the large display or offer all the fancy features advertised for the Zigbee mode.

Zigbee mode and Matter-related features

Switching to Zigbee mode requires you to remove the W100 from all Matter platforms or reset it. It takes about a minute for the W100 to load the Zigbee firmware, and after that, the setup process is similar to any other Aqara Zigbee device.

Once configured, the W100 Climate Sensor can bind with a thermostat. In my Aqara app, only the M3 built-in IR remote was supported. According to Aqara, the Radiator Thermostat E1 is supported too. Once both devices were paired, the W100’s display showed my air conditioner’s mode, fan speed, and target temperature. The middle button is used for navigation, while the plus and minus buttons adjust the settings.

The display also shows secondary temperature and humidity readings at the bottom, sourced from local outdoor weather data provided by Aqara. I tried binding it to another source through settings, but, sadly, Matter-connected sources didn’t work with it yet. It seems an Aqara Temperature and Humidity Sensor is needed for that.

The controls are convenient, providing a quick glance at essential climate measurements. While the control speed is slower than expected. It seems to take about two seconds for adjustments to take effect – sometimes it is longer, but it is fine for thermostat control.

In Zigbee mode, the Aqara hub bridges the device to Matter platforms, providing temperature and humidity sensors, plus three programmable buttons. However, once you bind it with a thermostat, these buttons won’t work or report changes on Matter platforms. To control the thermostat and display additional thermometer readings, you need to keep the W100 in Zigbee mode and disable the “Connect Thermostat” setting.

Strangely, the thermometer readings don’t show up in SmartThings when bridged, only the three programmable buttons are visible through the Hub M100 Matter bridge. For other platforms, the features are nearly identical to those in Matter mode.

Ambitious, but not ready for Matter

The Aqara W100 Climate Sensor feels like an ambitious product, but it’s somehow compromised and unfinished for Matter users. The features it offers in both Zigbee and Matter-over-Thread modes are solid, though the latter lacks some of the expected advanced functionality. That said, there are very few devices on the market that combine a generic switch and thermometers with support for both Matter and Thread. The W100 could be an important addition to the smart home ecosystem.

In Zigbee mode, it provides thermostat binding and secondary thermometer displays, and is available in Matter via an Aqara bridge like Hub M100.

However, the W100 leaves a lot to be desired. It currently doesn’t fully leverage Matter’s binding features to source from other temperature sensors or thermostats like those from Tado or Google Nest. Or, at the very least, it should be able to source data from other Matter devices added to Aqara’s Matter hub. But for now, that’s not the case.

If you’re considering this product, I recommend managing your expectations. For pure Matter use, some of the more advanced features are missing at the moment.

The Aqara W100 Climate Sensor is now available on Amazon and other Aqara-partnered retailers globally, priced at $39.99.