The Hunga-Tonga Eruption may have had something to do with the severity of this winter.
This eruption occurred slightly less than a year ago (2022 Jan 15) and was classified as a five on the Volcanic Explosivity Index(VEI). Some may even argue it was as much as a six. In the case of this volcanic eruption, satellites recorded the entire thing and showed the explosive plume reaching the mesosphere.
There have been many incidents of volcanic cooling in our history. The massive eruption of Mount Tambora in present-day Indonesia caused the Year Without a Summer in 1816. Many Volcanic Winters have been discovered by carefully examining historical records and ice cores from the arctic.
There are two schools of thought on the actual mechanism that creates this condition: a) the volume of material and b)the height at which the material is when it is blasted into the atmosphere. Once this gas and dust get in the jet stream, it is distributed worldwide.