2nd Polar Vortex 2025 Dates

2nd Polar Vortex 2025 Dates. It usually produces one later in winter, compared to an el niño. As you can see, a la niña phase has a higher chance of producing a polar vortex collapse event.

Winters with at least one polar vortex disruption/sudden stratospheric warming (ssw) are marked with a black outline (and years with two have two circles). It usually produces one later in winter, compared to an el niño.