Not very nice but I think this will work.. //float temperature = dht.getTemperature(); float temperature = dht.getTemperature()*9/5 + 32; if (isnan(temperature)) { Serial.println("Failed reading temperature from DHT"); } else if (temperature != lastTemp) { lastTemp = temperature; if (!metric) { temperature = dht.getTemperature()*9/5 + 32; //dht.toFahrenheit(temperature); }