This is an amazingly simple project with only one cheapish component being added. It's also a great way to see how Python code is used to read it and display the data to a screen or a spreadsheet.
Taking it from this point forward it is not difficult to format that output and send it to Weather Underground or other online weather services. Full-blown weather stations really just o this and include rainfall and wind direction and speed, so I'm wondering about some additional components to try and archive that, because commercial weather stations are pretty expensive now and mine is getting to its autumn years of life. I'll add that to my todo list.
Watch at Raspberry Pi Weather Station
Raspberry Pi weather station that reads temperature, pressure and humidity data from a BME280 sensor, and records it in a spreadsheet.The sensor used is from...