Answer:
Cool and dry
Explanation: Trees tend to be sensitive to climates, so when the conditions are good the trees grows faster which results in wider growth rings and in poor conditions the tree grows slower which results in it laying down less tissue and therefore a narrower ring size. Drought and a blizzard can also cause narrower ring too. Actually, a cool way to find out if the climate conditions were good is to measure the rings of a tree every month each year. If the rings were consistently the same then you know the climate stayed pretty much the same and etc.