It reminds me of the beginning of the "little ice age", which started with an ugly cold wet spring, and famine resulting from the crop failure.
My guess is heavy rains and high humidities occur going into the glacial period or dipping back into that period. The oceans control everything mid term. Rain represents heat leaving the oceans as water vapor. So it rains like crazy going in due to heat leaving the oceans. Energy is always entering the oceans due to visible sun light. So global cooling must require the rejection of that sunlight from the oceans. Ie - it rains like crazy.