Longer, cooler nights start tomorrow - PAGASA

MANILA, Philippines - The Philippines and other countries in the northern hemisphere would experience on Friday the autumnal equinox, which marks the beginning of shorter days and longer nights, the state weather bureau said yesterday.

“Philippine nights would be longer as the Sun approaches the celestial equator,” the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said.

PAGASA said the autumnal equinox would occur on Friday when day and night will have equal length on Earth.

PAGASA said the Sun’s declination is zero degrees and there are 12 hours of day and 12 hours of night at all points on the Earth’s surface. The noon altitude of the Sun is 90 degrees (the zenith) at the equator and diminishes to zero degrees at the poles.

Weather bureau officials also said the northeast monsoon will set in this October, bringing cooler weather to the country starting November.

If you’re in the northern hemisphere, the days will begin getting shorter after the autumn equinox and the nights will grow longer, PAGASA said.

This signifies the approach of winter in the northern hemisphere and summer in the southern hemisphere.

This is the time when the earth tilts upward on its axis, exposing the countries below the equator to more sun and those above it to less sun.

From October to February, the northeast monsoon brings cold winds from the north, creating cool and dry weather.