What Day Does Fall Start

The onset of fall, also known as autumn, is a seasonal transition that varies depending on the hemisphere and the specific definition used. In the Northern Hemisphere, where most of North America, Europe, and Asia are located, fall typically begins around September 22 or 23, and ends around December 21 or 22. This period is also known as autumn, and it’s characterized by the shortening of days, the cooling of temperatures, and the changing colors of leaves.

To be more precise, the astronomical start of fall in the Northern Hemisphere usually falls on the day of the autumnal equinox, which typically occurs on September 22 or 23 in the Northern Hemisphere. On this day, the sun crosses the celestial equator, marking the moment when day and night are approximately equal in length. After the autumnal equinox, the days start getting shorter, and the nights get longer, as the Earth continues its orbit around the sun.

In contrast, in the Southern Hemisphere, where countries like Australia, New Zealand, and South Africa are located, the start of fall typically occurs around March 20 or 21, and ends around June 20 or 21. This is because the seasons are reversed in the Southern Hemisphere, with the autumnal equinox occurring in March instead of September.

It’s worth noting that the exact start date of fall can vary slightly from year to year due to the Earth’s elliptical orbit around the sun and the resulting variations in the timing of the equinoxes. However, for most practical purposes, September 22 or 23 is widely recognized as the start of fall in the Northern Hemisphere.

Now, let’s take a closer look at the changing seasons and what they bring.

Seasonal Changes

As the Earth rotates and orbits the sun, different parts of the planet receive varying amounts of sunlight throughout the year. This variation in sunlight leads to changes in temperature, weather patterns, and the overall climate. The four main seasons – spring, summer, fall, and winter – are a result of this process, with each season bringing its unique characteristics and effects on the environment.

What Happens During Fall?

During fall, the days get shorter, and the nights get cooler. The reduced sunlight and cooler temperatures trigger a series of events in plants and animals, leading to the characteristic fall foliage, harvesting of crops, and preparation for the winter months. This season is also known for its festive atmosphere, with holidays like Halloween and Thanksgiving in the United States.

Why Do Leaves Change Color?

One of the most striking features of fall is the changing colors of leaves. As the days get shorter and the nights get cooler, the trees prepare for the winter months by slowing down their food-making processes. This reduction in chlorophyll production allows the hidden pigments of yellow, orange, and red to become visible, creating the vibrant colors of fall foliage. The exact shades and hues depend on the species of tree, the climate, and the soil conditions.

Conclusion

Fall, or autumn, is a season of transition, marked by the changing colors of leaves, the harvesting of crops, and the preparation for the winter months. The exact start date of fall can vary slightly from year to year, but September 22 or 23 is widely recognized as the beginning of this season in the Northern Hemisphere. As we explore the changing seasons and their effects on the environment, we gain a deeper appreciation for the natural world and the intricate processes that shape our planet.