Finding a pattern in weather data using R [closed]

During my work with historical yield data in barley, I observed that 2009 was a great year for grain yield, while 2015 was a really bad year for the same trait. Thus, to understand the difference between these two years, I requested weather data from the main barley production locations (A, B, and C) for 2009 and 2015. The parameters measured in the weather data, on a daily base, were minimum and maximum temp, rain, snowfall, and depth.

here is a link for the data: https://unl.box.com/s/8vq9i1i7egcvzv959h3j47v2a9ozo7u8

I will be truly grateful if you can help me answer the following questions:

What is the best way to compare these two years? How can we identify a pattern, if there is any, in 2009 and 2015? How can we plot this kind of data?

thank you so much in advance for your time and help