Those long dark winter nights need filling, so you made a New Year resolution to learn a new language, maybe Scala, or improve your programming skill. A worthy idea and to help you, here is a set of puzzles to challenge the professional Scala programmer or provide the the neophyte programmer with a wide variety of Scala examples to learn the language quicker...
Try the 99 puzzles  adapted by Phil Gold from those created by Werner Hett. With a few exceptions each problem has a Scala solution.
Or on langref.org  you will find a collection of typical problems faced by programmers and suggested solutions in Scala. The site also offers solutions in other languages  too so comparisons can be instructive.
While the Euler project  offers a fascinating set of problems to solve, some of which may require you to brush up your mathematical skills too. To get you started, Jan Burkhardt offers Scala source solutions  for a good number of them.
Perhaps for those of you living in the Southern Hemisphere a beach and a laptop would make a better venue. Have fun!