The Thingsee One thermometer and humidity sensor have some hysteresis issues, meaning, in effect, that the sensor reading lags behind the real environment. This is due to both sensors being enclosed within the hardware.
The heat produced by the battery and temperature changes in the electronics also affect the sensor readings.
In essence, their performance varies so greatly that temperature and humidity readings need to be calibrated on a case-by-case basis.
A rough starting point in using Thingsee Creator would be to set temperature and humidity values to be polled once an hour.