The continued eastward migration of the high pressure area over mainland Asia and the development of low pressure systems in the Indian sub-continent indicate the termination of the Northeast Monsoon (Amihan) season in the Philippines.

Current atmospheric and oceanic indices are still consistent with the moderate El Niño occurring in the equatorial Pacific. Forecast outputs of leading climate models likewise indicate the continuation of the warm event likely up to June 2010.

The Sun's motion allows it to pass the First Point of Aries (known as Vernal Equinox), an artificial location in the sky defined in our coordinate system as a place where the ecliptic and celestial equator meet. It marks the zero point of the Right Ascension grid, the celestial equivalent of longitude on Earth. Due to the wobbling motion of the Earth known as precession, the First Point of Aries now lies in Pisces. The Sun reaches this point on March 21 (Vernal Equinox), marking the beginning of spring in the Northern Hemisphere and autumn in the Southern Hemisphere. The length of day and night in both hemispheres is equal on this day.