Spring 2026 in the United States: Duration, Equinox, and Transition to Summer

In just two days, the United States and the Northern Hemisphere will officially welcome spring, a season that marks the beginning of profound changes in weather and nature. This period is characterized by gradually rising temperatures, longer daylight hours, the resurgence of plant life, and the reactivation of vital processes in the animal kingdom. Spring serves as the natural bridge to summer, establishing a seasonal cycle that will continue until late September.

How long does spring last and when does summer begin?

Spring lasts approximately three months (92 days and 17 hours), starting with the March equinox and ending when the June solstice occurs. In 2026, the spring equinox will happen tomorrow, Friday, March 20th, exactly at 10:46 a.m. Eastern Time, according to The Old Farmer’s Almanac. At this precise moment, the Sun crosses the celestial equator, an astronomical phenomenon that simultaneously marks the start of spring in the Northern Hemisphere and the beginning of autumn in the Southern Hemisphere.

The exact duration: from the March equinox until summer begins

Spring will end on June 20, 2026, giving way to summer. This seasonal change occurs at the June solstice, when the Earth reaches its maximum tilt toward the Sun. Summer, in turn, will last until September 22, marking the start of autumn in the Northern Hemisphere.

How long does summer last in the United States?

Summer lasts approximately three months and two days (92 days and 16 hours), starting on June 20, 2026, and ending on September 22 of the same year. Thus, the transition from spring to summer is almost imperceptible in terms of duration, although the changes in sunlight intensity and temperature are very significant. After summer, autumn extends until December 21, when winter begins again.

Why does the spring equinox not have a fixed date?

The start of spring varies between March 19, 20, or 21 because the Gregorian calendar does not exactly match the time it takes for Earth to complete one orbit around the Sun. The astronomical year lasts about 365 days and six hours, while the Gregorian calendar considers only 365 days. This difference is compensated by leap years, which add an extra day every four years. However, the adjustment is not perfectly precise, so the exact moment of the equinox shifts slightly from year to year, causing some variation of a few hours.

Complete seasonal cycle in 2026

• Winter: begins December 21, 2025, and ends March 20, 2026
• Spring: begins March 20, 2026, and ends June 20, 2026
• Summer: begins June 20, 2026, and ends September 22, 2026
• Autumn: begins September 22, 2026, and ends December 21, 2026

The vital role of seasons in natural cycles

The seasons are natural consequences of the solar system’s dynamics and serve essential functions for life on Earth. They regulate climate cycles, influence agricultural practices, determine animal migration patterns, and control the biological rhythms of plants and humans. Spring and summer, in particular, represent periods of maximum biological and energetic activity in the Northern Hemisphere.

Visible transformations during the spring transition

From an astronomical perspective, the Sun is positioned over the Earth’s equator during the equinox, causing days and nights to be nearly equal in length worldwide, with only a few minutes of difference, according to NASA. From that moment on, daylight hours increase progressively while nights shorten.

Climatically and biologically, temperatures steadily rise, initiating plant blooming and foliage recovery in trees. Simultaneously, many animal species begin reproductive or migratory cycles. These changes are also reflected in daily life, with increased outdoor recreational, sports, and social activities in anticipation of the warmer months ahead.