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Southern Hemisphere spring equinox arrives September 22
The astronomical spring equinox for 2026 is set to occur on Tuesday, September 22, at 21:05 in Paraguay and Uruguay, marking the official transition to spring in the Southern Hemisphere. While many countries in the region, particularly Argentina, traditionally celebrate the arrival of spring and Student Day on Monday, September 21, the actual astronomical event occurs a day later when the sun crosses the celestial equator.
In Argentina, the September 21 date is a deeply rooted cultural tradition associated with Student Day, honoring the legacy of Domingo Faustino Sarmiento. This often results in school holidays and widespread public celebrations in parks and plazas, even though the seasonal shift is technically delayed. In Uruguay, the equinox will also be observed on the 22nd, signaling the return of longer days and warmer temperatures.
Entities
Argentina · Colón · Domingo Faustino Sarmiento · Hipólito Yrigoyen Park · Instituto de Astrofísica de La Plata · Mendoza Police · NASA · Observatorio Astronómico Los Molinos · Paraguay · San Miguel de Tucumán · San Rafael · San Salvador de Jujuy