I’ve tried the DHT11 sensor modules at both Vcc 3.3V and 5.0V, and at both voltages the humidity values are bad. dfrobot has introduced a V2 DHT11 sensor module that changes the 10K pull-up to 4.7K.

The Anavi Thermometer Development board is fully compatible with the Arduino ... AM2302 temperature and humidity sensor and has slots for a mini OLED display, waterproof DS18B20 temperature ...