As it does so, you can see how it affects the measurements at the extremes - warm extreme temperatures become more common place, and cold extremes less common. (skepticalscience.com)
That does not mean we should do nothing, as the worst effects of warming extreme weather conditions and rises in sea levels are directly dependent on the extent of global temperature rise above 2C. (opednews.com)
In northern North America the difference in the 20RV is positive as blocking is associated with warmer extreme cold temperatures. (pacificclimate.org)