The fall equinox, officially marking the start to fall, arrives this Sunday, September 22, 2024, at 7:43am. The equinox occurs at the same moment worldwide when the sun is directly over the equator making day and night exactly the same amount of time. The apparent equal hours of daylight and darkness result from the refraction of sunlight, or the bending of light’s rays, the National Weather Service reports. This refraction causes the Sun to appear above the horizon when it is actually below the horizon.

Have you ever wondered what an equinox is? The word “equinox” comes from Latin aequus, meaning “equal,” and nox, “night.” During an equinox, the Sun crosses the “celestial equator, which is an imaginary extension of Earth’s equator line into space. The equinox occurs precisely when the Sun’s center passes through this line.

After Sunday (the fall equinox), days become shorter and nights longer as the Sun continues to rise later and nightfall arrives earlier. Other changes are happening too. Birds begin flying south, temperatures will begin getting cooler, leaves change colors, but most significant is the change in daylight.

Sources: The National Weather Service
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