Even though news stories across the media are talking about the end of the decade and the start of a new decade, whether or not it is really the end of the decade is a matter of some debate. For climatologists, the next normal period of 1991-2020 is still a year from ending. Normal temperature and precipitation are calculated over 30 year periods and are updated every 10 years because the process for producing high-quality normals is quite involved. So for us, the next year is the end of the decade, not the start of a new decade. You can read more about the question and what normals are in this Forbes.com article from UGA’s Dr. Marshall Shepherd here.