The article mentions it at the end: This is quite a well-studied period that was probably linked to a large El Niño event - the climate cycle associated with s

The article mentions it at the end: This is quite a well-studied period that was probably linked to a large El Niño event - the climate cycle associated with shifting pressure patterns and a weakening of the trade winds in the Pacific. The world warmed, apart from Europe which had a deep cold spell. And it probably had an impact on the outcome of WWII. The harsh winters at the time frustrated Hitler's armies as they invaded the Soviet Union.