Ecowitt WN31 (WH31) Multi-Channel Temperature and Humidity Sensor

The Ecowitt WN31 is an additional wireless temperature and humidity sensor for the Ecowitt WS3900, allowing you to monitor conditions in another location without changing the main outdoor temperature and humidity readings from your weather station.

Use one to keep track of temperature and humidity in places such as a greenhouse, garage, shed, sleepout, storage area or another sheltered outdoor location — or add several sensors if you want to compare conditions around your property.

The Ecowitt WN31 has its own small LCD display for checking the current temperature and humidity where the sensor is located. Its readings are also transmitted wirelessly to the Ecowitt WS3900, where they can be viewed on the console and, when your weather station is connected online, through the Ecowitt app and ecowitt.net.

Monitor Temperature and Humidity in More Locations

The Ecowitt WS3900 already monitors its main indoor and outdoor conditions, but there are often other places where temperature and humidity matter.

The Ecowitt WN31 lets you add a separate measurement point wherever you need one. This can be useful for monitoring areas such as:

• greenhouses
• garages and workshops
• sheds and outbuildings
• sleepouts
• storage areas
• different rooms within the home
• sheltered outdoor locations

Because each Ecowitt WN31 operates on its own channel, you can identify and follow each location separately.

Up to Eight Temperature and Humidity Channels

The Ecowitt WS3900 supports up to eight compatible additional temperature and humidity channels.

This means you can begin with a single Ecowitt WN31 and add more later if you want to monitor several areas around your home or property.

Each sensor can be assigned to its own channel, making it easy to distinguish between the different locations you are monitoring.

See the Reading on the Sensor, Console or Phone

The Ecowitt WN31 has its own LCD display, so you can see the current temperature and humidity directly at the sensor.

The readings are also sent to the Ecowitt WS3900 console using a wireless radio signal and can be displayed there alongside your other weather information.

If your Ecowitt WS3900 is connected to your home Wi-Fi and the internet, the additional temperature and humidity data can also be uploaded to Ecowitt for viewing through the Ecowitt app and ecowitt.net.

This also allows you to look back at graphs and historical records rather than seeing only the current reading.

Simple Wireless Installation

The Ecowitt WN31 communicates directly with the Ecowitt WS3900 using a wireless radio signal, so the sensor itself does not need Wi-Fi or an internet connection.

It operates from two AA batteries and transmits an updated temperature and humidity reading approximately every 61 seconds.

The Ecowitt WN31 can be wall mounted or hung in a suitable location.

For outdoor monitoring, position the sensor in a sheltered location away from direct sunlight and heavy rain so that the reading reflects the surrounding air conditions rather than heating from the sun or direct exposure to weather.

Why Choose the Ecowitt WN31?

• Monitor another location — add temperature and humidity readings from elsewhere around your home or property.
• Up to eight channels — use multiple compatible sensors with the Ecowitt WS3900 if you want to monitor several areas.
• Built-in LCD display — see the current reading directly where the sensor is installed.
• Readings on the Ecowitt WS3900 console — additional temperature and humidity channels can be displayed on your weather-station console.
• View data in the Ecowitt app — follow current readings and historical trends when your Ecowitt WS3900 is connected online.
• Wireless operation — no cable or Wi-Fi connection is required between the Ecowitt WN31 and the Ecowitt WS3900.

FAQ’s

Can the Ecowitt WN31 operate on its own?

The Ecowitt WN31 has a small display showing its current temperature and humidity reading, but to become part of your weather-monitoring system and provide console, app and historical data, it requires the Ecowitt WS3900.

Will the Ecowitt WN31 replace the outdoor temperature and humidity reading from my Ecowitt WS3900?

No. The Ecowitt WN31 is an additional multi-channel sensor. It adds another temperature and humidity location rather than replacing the main outdoor temperature and humidity reading from the Ecowitt WS3900 weather station.

Will Ecowitt WN31 readings appear on the Ecowitt WS3900 console?

Yes. The Ecowitt WS3900 can receive and display up to eight compatible additional temperature and humidity channels, including Ecowitt WN31 sensors.

Can I use more than one Ecowitt WN31?

Yes. The Ecowitt WS3900 supports up to eight compatible additional temperature and humidity channels, allowing several Ecowitt WN31 sensors to be used in different locations.

Does the Ecowitt WN31 need Wi-Fi?

No. The Ecowitt WN31 sends its readings directly to the Ecowitt WS3900 using a wireless radio signal.

Your Ecowitt WS3900 uses your home Wi-Fi and internet connection if you want the additional sensor data uploaded for viewing through the Ecowitt app and ecowitt.net.

WN31 Manual