During the spring, the sun rises earlier in the morning and sets later in the afternoon. March, April and May are considered to be spring in the Northern Hemisphere, whereas September, October and November are spring in the Southern Hemisphere. Many cultures have festivals in honor of spring's arrival.
One of the marked characteristics of spring, at least in non-tropical regions, is an increase in temperature. During this season, Earth's axis tilts further towards the sun, which causes temperatures to rise, frost to melt and snow to be replaced with rain. These changes in weather cause flowers to bloom and trees to grow new leaves. Many animal species give birth to their young in the springtime. On the spring equinox, which occurs between March 20th and 22nd and is often recognized as the first day of spring in the Northern Hemisphere, both day and night are exactly 12 hours long.
Various cultures have different ways of celebrating spring. In Australia, where spring lasts from September to November, an annual series of horse races called the Spring Racing Carnival draws crowds to Melbourne. In Iran, the first day of spring is celebrated on March 21st with large festivals and family parties. In India, a festival called "Holi" honors the end of the winter season and beginning of spring with colorful displays and costumes.