The first day of spring in 2015 arrives on Friday, March 20th at approximately 3:45 pm, PDT as the sun passes over the equator on it's annual return trip into the northern hemisphere.

Like last year, for many here in Lake Tahoe and the western United States, this year it seems like spring has been here for several weeks. The marginal, and nearly unnoticeable winter will now fade away.

Balance of Light and Dark
In the third week of March each year, the Vernal Equinox occurs, when the sun is over the equator at high noon and for a brief time and is shining (nearly) "equally" in both the Northern and Southern hemispheres.

Here in Lake Tahoe this year, the Vernal Equinox is the astrological first day of spring and this year, spring weather is clearly evident as flowers bloom, birds sing and temperatures rise.

North Pole
The sun will travel northward, relatively, until the third week in June, when the Northern Hemisphere has its longest day, i.e., period of daylight, known as the Summer Solstice. The sun then heads southward again and crosses the equator on the day of the Autumnal Equinox in September.

For more about the Vernal Equinox, visit www.timeanddate.com.

To check the position of the sun, and the angle of light and shadows at Lake Tahoe, check in with Tahoetopia.com's live, streaming webcams on a regular basis.

Above is a diagram of the Earth's seasons as seen from the north. Far right: December solstice. Source: Wikipedia