The Si7021 device provides temperature and humidity sensor readings with an I2C interface.
I2cConnectionSettings settings = new I2cConnectionSettings(1, Si7021.DefaultI2cAddress);
I2cDevice device = I2cDevice.Create(settings);
using (Si7021 sensor = new Si7021(device, Resolution.Resolution1))
{
// opne heater
sensor.Heater = true;
// read revision
byte revision = sensor.Revision;
// read temperature
double temperature = sensor.Temperature.Celsius;
// read humidity
double humidity = sensor.Humidity;
}
https://cdn.sparkfun.com/datasheets/Sensors/Weather/Si7021.pdf