As for the weather 400 years ago there was no official record kept back then. But sometime about 7-8 years ago a small group of people in europe decided to try and find some clues of what really happened.
Digging into and going over old archives revealed little, so someone suggested going to some of the older monasteries around europe and sure enough they allowed them to have a look and even helped them and they found enough written about daily life to give them a very good idea of what took place over passage of many years. The rain's and storms they have seen in europe over the last few years is only the beginning.
So unless the Sun does a complete turn around it's only going to get colder and how bad it will get this time around? No one really knows it's almost imposable to predict what may happen more than a year or two out into the future and even then it's a shot in the dark.
Here is a link to a doc that summarizes european weather reportrd at the time
http://www.breadandbutterscience.com/Weather.pdf
you have to remember there were no thermometers in general use until late in the 1700’s
so they report frost and cold as they describe dismal conditions developing
it is a long and useful read