I agree with the premise, weather variability is due to solar activity (sunspot or no sunspots).
But, who was keeping score in 1600 to give us this data. What assumptions made it possible to speculate at sunspot activity that long ago.
There were those who watched the sun then, but it would not have been consistently been organized since then.
From Wikipedia:
“The Maunder Minimum occurred between 1645 and 1715 when very few sunspots were observed. This was not due to a lack of observations; during the 17th century, Giovanni Domenico Cassini carried out a systematic program of solar observations at the Observatoire de Paris, thanks to the astronomers Jean Picard and Philippe de La Hire. Johannes Hevelius also performed observations on his own.”