Spring has Sprung...

While we were holding on to our hats, shoveling snow, and filling sand bags, spring snuck right in....the first day of Spring was Sunday March 20.

Seasons are major divisions of the year, generally based on periodic changes in weather. They occur due to the changing tilt of the Earth's axis in relation to its orbit around the Sun (astronomical seasons), and the variations in plant life, animal life, and weather this causes. Earth's polar and temperate regions, which see a greater variation in temperature, experience four astronomical seasons: spring, summer, autumn (fall), and winter. The planet's tropical and subtropical regions do not see significant variations in temperature, but rather differences in the amount of rainfall, so these experience only two astronomical seasons: a dry season, and a wet (monsoon) season.

The change in astronomical seasons coincides with days on which the planet's axis is tilted closest or furthest from the sun (solstices), and those on which the sun is directly over the equator (equinoxes). Seasons in the Northern Hemisphere are opposite of those in the Southern Hemisphere, meaning when one experiences spring, the other experiences autumn. Likewise, when one hemisphere experiences summer, the other experiences winter:

• The spring equinox marks the first day of the spring season in the Northern Hemisphere, while marking the first day of autumn in the Southern Hemisphere. On this day, the Sun is directly over the earth's equator, and daylight lasts 12 hours in both Hemispheres.
• The summer solstice marks the first day of the summer season in the Northern Hemisphere, and the first day of winter in the Southern Hemisphere. On this day, the Northern Hemisphere is tilted closest to the Sun and experiences the most hours of daylight in the year.
• The autumnal equinox marks the first day of the fall season in the Northern Hemisphere, while marking the first day of spring in the Southern Hemisphere. On this day, the Sun is directly over the earth's equator, and daylight lasts 12 hours in both Hemispheres.
• The winter solstice marks the first day of the winter season in the Northern Hemisphere, and the first day of summer in the Southern Hemisphere. On this day, the Northern Hemisphere is tilted furthest from the Sun and experiences the least hours of daylight in the year.