At the start of spring (spring equinox), day and night are approximately 12 hours long (at the equatorial plane) and the Sun is at the midpoint of the sky. Our north pole tilts towards the Sun.
NOTE-"the north pole tilts toward the sun." that is true on summer solstice, but in December the south pole tilts toward the sun. At the equinoxes the tilt is parallel to the sun.
First day of spring in the Northern Hemisphere
In general, the four seasons correspond to the relative position of the sun to the earth. Astronomical determination of spring is calculated according to when the sun passes through the equatorial plane. When going from winter to spring, the sun is moving north; as soon as the sun crosses the equator, we call it spring. (This applies to places north of the equator.)
First day of spring in the Southern Hemisphere
The "official" date of spring south of the equator (official is corresponding to the first day of fall in places north of the equator) would be around September 20/21, depending on when the sun crosses the equator.
Countries such as Australia and New Zealand, however, designate the first day of September as the official first day of spring (climatological counterpart). Preference between these two methods varies across Europe. Many east Asian countries use lunar dates to determine the beginning of spring.
The climatological spring as defined by the World Meteorological Organization began on March 1, 2011.
The ecological spring begins locally with the beginning of the growing season. Usually in temperate climates when the mean daily temperature reaches 6 degrees C/42 degrees F. This can be as early as February in mild climates. and as late as April or May in cool climates.
March 20, 2011 is the first day of Spring in 2011.
Mar 1 2011
The first day of spring break after spring quarter 2011 is Friday June 8th and classes begin for summer quarter 2011 on Monday June 20th.
March 21 is the first day of Spring Break for 2011 at the U of A.
The same day as the rest of the country.... March 20, 2011
The first day of spring is an equinox, as is the first day of autumn. Solstices occur on the first day of winter and the first day of summer.
Who Knew - 2010 First Day of Spring 3-57 was released on: USA: 21 March 2011
March 21st is the official day of spring but March 22nd is the first full day of spring.
March 20th, was the first day of spring in 1965.
The first day of Spring in France is the 20th I think.
The Scientific name for the first day of spring is the Vernal Equinox!
The first day of spring in 1960 was March 20.
On the first day of spring the season changes. Spring comes and you say 'goodbye' to winter.
It was the first FULL day of spring, the vernal equinox fell on March 20th the first day (actual) of spring.
The first day of spring 2009 fell on March 20.
In 2004 the first day of spring occurred on March 20.
The First Day of Spring in NZ is September 1, 2010.
The first day of the astronomical spring in Canada as defined by the International Astronomical Union is March 20th. The first day of the climatological spring as defined by the World Meteorological Organization is March 1. The ecological spring begins locally with the beginning of the growing season. This can be as early as February on the west coast and as late as April or May elsewhere in Canada.
The Vernal Equinox determines the first day of spring. The Autumn Equinox is what determines the first day of fall.
Sunday March 13th, 2011.
The date of Easter is determined by the first day of spring. Easter is held on the first Sunday after the first full moon after the first day of spring.
Spring srats on March 21st, 2011.
The first day of spring in 2014 will fall on March 20th. This will be a Thursday.
The first day of spring in 2008 was March 20th.