My kids brought home a little DIY no-tech weather station and they asked me to help them build it. I'm always excited about any opportunity to geek out with them so we spent 20 minutes or so building the thing and then a week or so collecting data in an excel spreadsheet.
Now we've decided to take things to the next level and build one of our own, this is a super popular project so there are tons of resources available online.
I ended up looking around and buying the sparkfun weather station kit which includes all of the mechanical sensors needed. It has a weather vane, an anemometer, and a rain gauge. I also purchased a "weather hat" from Perino, which is a collection of digital sensors (humidity, lux, temperature, etc) as well as a couple of inputs that can connect to the weather station wind and rain data.
The fun part will be writing code to read the sensor data and pipe it to an app.
Update: The hat has arrived and now I am faced with the problem of being way more interested in this project than anything I have going on at work!