Adafruit Si7021 Temp Humidity Sensor Breakout - STEMMA QT

Overview

Add precise environmental sensing to your next project with the Adafruit Si7021 STEMMA QT Breakout. Built around the reliable Si7021 digital sensor from Silicon Labs, this board delivers accurate temperature and relative humidity readings over a simple I²C interface, making it ideal for weather stations, indoor air monitoring, HVAC logging, and IoT systems.

The Si7021 offers ±3% RH accuracy (0–80% RH range) and ±0.4°C temperature accuracy across –10°C to +85°C. With digital I²C output, you avoid analog calibration issues and can integrate directly with microcontrollers like Arduino, Raspberry Pi, and Feather boards.

Designed for Fast, Clean Integration

This breakout uses the STEMMA QT form factor with dual JST SH connectors, fully compatible with SparkFun Qwiic cables. That means you can plug it in without soldering and even daisy-chain multiple I²C devices in seconds.

For traditional prototyping, all pins are also broken out to 0.1" headers (included, soldering required).

Specification

Technical details for Adafruit Si7021 Temp Humidity Sensor Breakout Board.

Pinout