@ instructables.com show us an easy to build IoT weather station able to measure temperature, dew point, humidity, pressure, light index, and rain. He writes:
A weather station is a fun project that teaches you a ton about electronics with the added benefit being an actually useful little device. The project requires a bunch of cheap parts and sensors totaling less than $15, and the whole thing ends up fitting in your hand. The station creates a web site that monitors temperature, dew point, humidity, pressure, light index, and rain (Thingspeak channel). It’s a pretty easy set up, and you’ll just need some basic electronics skills to get it going.
Easy IoT Weather Station With Multiple Sensors – [Link]