Changes in Seasons

Reasons for Seasons

The seasons on Earth change every 3 months. There are two main

causes for the change of seasons:

1. The axis of the Earth is tilted 23.5º

2. The Earth revolves around the Sun once a year

If the Earth tipped over a few more degrees, the seasons would be more extreme (winter would be colder and summer would be much hotter).

If the Earth was tipped less, the seasons would be less extreme.

If the Earth stood straight up, the Earth would have never have seasons again, and every place would have the same climate all of the time. However, each location would have a different climate.

The First Day of Each Season1. The first day of winter is called the Winter

Solstice. It is usually between December 20 and 22.

2. The first day of spring is the Vernal Equinox. It is usually between March 20-23.

3. The first day of summer is called the Summer Solstice. It is usually between June 20 and 22.

4. The first day of autumn (fall) is called the Autumnal Equinox. It is usually between

September 20 and 23.

The Southern Hemisphere has opposite seasons from us. For example, June 21

is the first day of Winter in Australia. You would not want to go there on your

summer vacation.

Places close to the Equator do not

experience very big seasonal changes. This is because they receive a more direct angle of sunlight all year long.

Seasonal Facts

1. In the summer, the Northern Hemisphere takes in more energy than it gives off. That it one reason why it is hotter.

2. In the winter, the Northern Hemisphere gives off more energy than it takes in. That is one reason why it is cooler.

3. The sun reaches the highest altitude at 12 noon each day. The Sun is never overhead in NYS, or any other place that is not between the Tropics.

Spring SeasonSpring is one of the four conventional temperate seasons, following winter and preceding summer. There are various technical definitions of spring, but local usage of the term varies according to local climate, cultures and customs. When it is spring in the Northern Hemisphere, it will be autumn in the Southern Hemisphere and vice versa. At the spring equinox, days are approximately 12 hours long with day length increasing as the season progresses.

Winter Season

Winter is the coldest season of the year in polar and temperate climates,

between autumn and spring. Winter is caused by the axis of the Earth in that hemisphere being oriented

away from the Sun. Different cultures define different dates as the start of winter, and some use a definition based on weather. When it is winter in the Northern

Hemisphere, it is summer in the Southern Hemisphere, and vice versa. In many regions, winter is

associated with snow and freezing temperatures

Summer SeasonSummer is the hottest of the

four temperate seasons, falling between spring and autumn. At the

summer solstice, the days are longest and the nights are shortest, with day-

length decreasing as the season progresses after the solstice. The date

of the beginning of summer varies according to climate, tradition and

culture. When it is summer in the Northern Hemisphere, it is winter in

the Southern Hemisphere, and vice versa.

Autumn Season

Autumn, also known as fall in North American English, is one of the

four temperate seasons. Autumn marks the transition from summer to winter, in

September (Northern Hemisphere) or March (Southern Hemisphere), when the

arrival of night becomes noticeably earlier while the arrival of day becomes noticeably

later, and the temperature cools down considerably. One of its main features is the shedding of leaves from deciduous

trees.