Meross MS120H Review: A Multi-Metric Hygrometer Built for the Meross Matter Hub
The Meross Smart Multi-Function Hygrometer and Thermometer MS120H is a battery sensor that goes well beyond a basic temperature and humidity gauge, adding dew point, absolute humidity and vapor pressure deficit to its 1.9 inch display. Its claim to a smart home runs through the Meross Matter Smart Hub (MSH450P), which the sensor reaches over low-power Bluetooth and which republishes it into Matter, Apple Home, Alexa, Google Home and SmartThings. With an IP66 body rated from -20 C to 60 C, it suits greenhouses, garages and outdoor storage as much as a living room, and its single CR123A cell is rated to last about three years. The trade-off is the hub: buy the sensor alone and you get a capable standalone meter, not a connected device.
- Meross and Matter households
- Greenhouses, garages and outdoor storage
- Rooms where a reading must be visible without a phone
- Buyers who want more than temperature and humidity
Pros
- Reports temperature, humidity, dew point, absolute humidity and vapor pressure deficit, more than a standard hygrometer
- 1.9 inch display shows the reading at a glance and switches between the five parameters
- IP66 water and dust resistance with a -20 C to 60 C operating range for indoor and outdoor spots
- Up to 120 days of local data and up to two years of cloud history, with app charts and export
- 100dB adjustable buzzer plus app alerts on temperature or humidity conditions
- Single CR123A battery rated up to about three years and easy to replace
- Reaches Matter, Apple Home, Alexa, Google Home and SmartThings through the Meross Matter Smart Hub
Cons
- Not a Matter device itself: the connected features all require the Meross Matter Smart Hub (MSH450P)
- No barometer, air quality, occupancy, time, date or weather forecast
- Meross publishes no dimensions, weight or screen resolution
- Indoor rated for weather resistance rather than a full outdoor appliance
Who is the Meross Smart Multi-Function Hygrometer and Thermometer MS120H for?
It is aimed at two kinds of buyer. The first already owns or plans to add a Meross Matter Smart Hub, and wants a climate sensor that feeds Matter automations while showing the reading on its own 1.9 inch display. The second wants a rugged standalone meter for a greenhouse, a garage, a wine store or a workshop, where the IP66 body and the wide -20 C to 60 C operating range matter more than app integration. Because the sensor talks to the hub over low-power Bluetooth rather than Wi-Fi, Zigbee or Thread, it is a good fit for battery life and for spots where Wi-Fi does not reach, but the connected half only works once the hub is present.
What the Meross MS120H offers
The headline is the measurement set: alongside temperature and relative humidity it reports dew point, absolute humidity and vapor pressure deficit, five parameters a standard hygrometer leaves out, all switchable on the 1.9 inch screen. Meross rates accuracy at up to plus or minus 0.2 C and plus or minus 2% RH. Monitoring continues in the background, with up to 120 days of data stored locally and up to two years in the cloud once the hub is connected, and the app can chart trends and export the history. A built-in buzzer rated at 100dB with adjustable volume, plus app notifications, alerts when the reading crosses a set condition, and the display carries a low battery indicator. The single CR123A battery is replaceable and rated up to three years.
What to know before you buy
The decision that matters is the hub. The MS120H is not a Matter device and joins no ecosystem on its own: it speaks Bluetooth to the Meross Matter Smart Hub (MSH450P), and the hub is what provides Matter, Apple Home, Alexa, Google Home and SmartThings support as well as the cloud history and the automations. Meross sells the sensor on its own and as part of the hub Starter Kit, so buyers who want the smart half should pair it with the hub rather than expect the sensor to connect directly. The sensor is indoor rated for weather but not a full outdoor appliance, and Meross publishes no dimensions, weight or screen resolution for it. There is no barometer, so it reports vapor pressure deficit rather than atmospheric pressure, and no air quality, occupancy, time, date or weather forecast on the screen.
Is the Meross MS120H worth it?
For anyone already in the Meross ecosystem, or willing to add the Matter hub, the MS120H is a sensible pick: it delivers the widest set of climate readings in its class, a readable display, a weatherproof body and a three-year battery on a single replaceable cell. Bought as the standalone sensor it is still a capable multi-metric meter for a greenhouse or a cellar, just without the app history, alerts and Matter automations that need the hub. The main thing to budget for is the hub if connected control is the point, and to weigh the missing barometer and the unlisted dimensions if those matter to you.
Frequently asked questions
Does the Meross MS120H need a hub?
For the smart features, yes. The sensor connects over low-power Bluetooth to the Meross Matter Smart Hub (MSH450P), and the hub provides the Matter, Apple Home, Alexa, Google Home and SmartThings support, the cloud history and the automations. Bought on its own it still works as a standalone thermometer and hygrometer with its display and local logging.
What does the Meross MS120H measure?
Five parameters: temperature, relative humidity, dew point, absolute humidity and vapor pressure deficit (VPD). Meross rates temperature accuracy at up to plus or minus 0.2 C and humidity at up to plus or minus 2% RH. It has no barometer, so it does not report atmospheric pressure.
Can the Meross MS120H be used outdoors?
It carries an IP66 water and dust resistance rating and is specified to operate from -20 C to 60 C (-4 F to 140 F), which Meross presents as suitable for greenhouses, garages and outdoor storage. Treat it as a weatherproof sensor for sheltered spots rather than a fully submersible outdoor device.
How long does the battery last and what type is it?
It runs on a single replaceable CR123A battery rated by Meross at up to about three years. The display carries a low battery indicator.
Does it work with Home Assistant?
Home Assistant can reach it over Matter through the Meross Matter Smart Hub, since Home Assistant is a certified Matter controller. The Meross line also has a community Home Assistant integration (meross_lan), but support for this exact model there depends on that project adding it.


