To cite package ‘clifro’ in publications use:

  Seers B, Shears N (2015). “New Zealand's Climate Data in R - An
  Introduction to clifro.” The University of Auckland, Auckland, New
  Zealand.
  <http://stattech.wordpress.fos.auckland.ac.nz/2015-02-new-zealands-climate-data-in-r-an-introduction-to-clifro/>.

A BibTeX entry for LaTeX users is

  @TechReport{,
    title = {New Zealand's Climate Data in R --- An Introduction to clifro},
    author = {Blake Seers and Nick Shears},
    institution = {The University of Auckland},
    address = {Auckland, New Zealand},
    year = {2015},
    url = {http://stattech.wordpress.fos.auckland.ac.nz/2015-02-new-zealands-climate-data-in-r-an-introduction-to-clifro/},
  }