The BME280 sensor is an inexpensive i2c device that measures temperature,pressure, humidity and altitude (calculated using the pressure measurement) . It works with 3.3V or 5V logic devices. With this example you can display the readings on a 128x64 OLED i2c screen.
Step 1: PARTS
Step 2: Wiring
Power the Arduino with a 6-20 V source such as two 18650 (7.4V) rechargeable batteries. The screen and BME 280 sensor can both be powered with the 3.3 V pin on the Ardiono
Step 3: CODE
This is the Arduino code and libraries to display temperature, pressure, humidity and altitude.