The Shrinkulator
No, this has nothing to do with Seinfeld character George Costanza and a famous scene involving swimming in a cold pool.
Instead, wood shrinks and expands as humidity levels change – as was demonstrated in an article I posted a few years ago.
If you have lots of time, you could put a sample of wood out in your shop and measure its dimensions every day for a year to get an idea of seasonal humidity swings and how the affect the wood for your projects. Or, you could plug your numbers into the Shrinkulator and see how much different species of wood will move based on your local humidity conditions. A very useful utility to help anticipate the impact of seasonal changes and your construction methods.