The WN38 Black Globe Thermometer measures and displays the black globe temperature only, which can be viewed on screen (see sensor matrix), through the Ecowitt app or website..

The WN38 is a professional, wireless black globe temperature sensor designed for long-term outdoor monitoring. Its core value lies in accurately measuring "perceived temperature," and based on this, combining with your weather station data to provide the WBGT (Wet Bulb Globe Temperature) index, which directly evaluates the heat stress imposed by the environment on the human body.

To display WBGT (Wet Bulb Globe Temperature) data in the app, the WN38 must be used together with an Ecowitt outdoor temperature and humidity sensor from either an outdoor array (WS69, WS90 etc) or the WN32 outdoor sensor.

The collected data can be transmitted via an Ecowitt Wi-Fi Gateway or displayed on a compatible receiver console (both sold separately). Once Wi-Fi configuration is completed, data can be viewed in real time through the Ecowitt app, WS View Plus app, or on the receiver console. Our demonstration WN38 sensor can be seen here paired with a WittBoy Pro (HP2564) which went online 26th May 2026.

Features

• Brass with a matte black coating on the surface, standard size, perfectly simulates human heat absorption 
• LED display for current reading
• IP66 sealed globe sensor
• Configure for use with Ecowitt gateway or consoles (only TFT console displays data on screen)
  
• Only 1 WN38 supported by each Console or Gateway
• Upload data to the Ecowitt weather server to view history graphs and download the data from the website
  
• Surface, pole or wall mountable
• 868MHz UK / European frequency 

Includes

• 1 x WN38 Black globe thermometer
• 1 x Mounting bracket
• 1 x User Manual
• 2 x U-Bolts for mounting on a pole
• 4 x Threaded nuts for U-Bolts (M6 size)
• 1 x SUS304 M3*12 Screw (horizontal installation)
• 1 x SUS304 M3*24 Screw (vertical installation)
• 4 x PA4.8×32 Screws (vertical installation) 
• 1 x L-shaped Hex Wrench
• 1 x 8 mm Single-Head Wrench (Carbon Steel) 

Technical & Manual

• Black globe diameter φ60 mm
• Black globe material Brass with a matte black surface coating
• Waterproof Rating IP66
• Temperature Range -40°C to 125℃ (-40℉ to 257℉)
• Temperature Accuracy ±1℃ (±1.8℉)
• Temperature Resolution 0.1℃ (0.2℉)
• Transmission distance in open field: 100 meters (300 feet)
• Operating Temperature Range of LCD Screen -10°C to 50°C(14℉ to 122℉)
• Operating Temperature Range of the Plastic Casing -40°C to 60°C(-40℉ to 140℉)
• IP66 rated sensor transmitter and probe sensor
• 868MHz UK / European frequency
• Sensor reporting interval: 60 seconds
• May require console or gateway firmware update as a new sensor
• Power: 1 x AA 1.5V LR6 Alkaline battery estimated 12 months use

A copy of the WN38 manual is available here for viewing.