Thanks for sharing your code. After analyzing my data and comparing it to your code and the notes in your program, I'm starting to think my data stream is structured slightly different. I see some patterns related to the rain indicator but I could not see any changes in data in respect to temperature or wind. Seeing as I want external humidity, I would have to use my own sensor (probably a DHT22/AM2302) which usually also includes temperature and the rain gauge is just a simple reed switch, I think I will work on interfacing directly to the sensors with an Arduino. For the anemometer, I'm going to try reading the encoder directly, similar to these two blog posts.
http://www.100randomtasks.com/weather-station-remodel
http://www.100randomtasks.com/weather-station-part-ii
Let me know if you are interested in seeing my collected data. Thanks again for your help.