For example, the late 1770s (particularly 1777) to the late 1780s the winters were particularly harsh. The winter of 1777
made Valley Forge unbelievably bad! Bad European winters in the late 1780s caused crop failures throughout Europe. It hit France particularly hard and set the stage for the French Revolution. We know all of this from written records from the participants at the time and we have actual temperature measurements. Upper-class gentlemen often had a hobby of monitoring the weather such as our own Thomas Jefferson, recording the temperature with these new-fangled thermometers was something they did. (Thermometers about 100 years old at that time.) So we have the records and it was quite bad!
I forgot to add that was in the period known as ‘The Little Ice Age” 1300 - 1850. So, harsh winter weather was the norm. There’s been a warming trend since 1850.