Spring is the most fickle season when it comes to weather in the Pacific Northwest. One day it is unseasonably warm, with temps in the 80s, ,and people are wearing short pants and polo shirts. The next day the temperature is in the 30s, and light snow is falling or there is a hail shower.
This can make flight training a challenge—not only are you at the whims of Mother Nature (who frankly sometimes behaves like a drunken hockey mom), but you also find yourself bringing an extra jacket or sweatshirt on your flight as a precaution. I tell my learners it is better to have that extra layer with you and not need it, than need it and not have it. I learned a long time ago to keep an extra jacket with my flight gear—one for me, one for my learners if needed. Getting too cold in the cockpit is bad for learning.