Climate of the Philippines

The Philippines has five types of climates: tropical rainforest, tropical monsoon, tropical savanna, humid subtropical and oceanic (both are in higher-altitude areas) characterized by relatively high temperature, oppressive humidity and plenty of rainfall. There are two seasons in the country, the wet season and the dry season, based upon the amount of rainfall.[1] This is also dependent on location in the country as some areas experience rain all throughout the year (see Climate types). Based on temperature, the warmest months of the year are March through October; the winter monsoon brings hotter air from November to February. May is the warmest month, and January, the coolest.[2]

Climate map of the Philippines based on the Modified Coronas' Climate Classification, based on the type of rainfall distribution during the 1951-2010 period.
Evening thunderstorms bringing rain over the Philippines is common from March to October.

Weather in the Philippines is monitored and managed by the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).

Rainfall

Monsoons are large-scale sea breezes which occur when the temperature on land is significantly warmer or cooler than the temperature of the ocean. Most summer monsoons or southwest monsoons (Filipino: Habagat) have a dominant westerly component and a strong tendency to ascend and produce copious amounts of rain (because of the condensation of water vapor in the rising air). The intensity and duration, however, are not uniform from year to year. Winter monsoons or northeast monsoons (Filipino: Amihan), by contrast, have a dominant easterly component and a strong tendency to diverge, subside and cause drought.

The summer monsoon brings heavy rains to most of the archipelago from May to October. Annual average rainfall ranges from as much as 5,000 millimeters (197 in) in the mountainous east coast section of the country, to less than 1,000 millimeters (39 in) in some of the sheltered valleys. Monsoon rains, although hard and drenching, are not normally associated with high winds and waves.

At least 30 percent of the annual rainfall in the northern Philippines can be traced to tropical cyclones, while the southern islands receiving less than 10 percent of their annual rainfall from tropical cyclones. The wettest known tropical cyclone to impact the archipelago was the July 1911 cyclone, when the total precipitation for Baguio was distributed over the four days as: 14th – 879.8 mm (34.6 in), 15th – 733.6 mm (28.9 in), 16th – 424.9 mm (16.7 in), 17th – 200.4 mm (7.9 in);[3][4] followed by extraordinary drought from October 1911 to May 1912, so that the annual amount of those two years were hardly noticeable.

Typhoons
Main article: Typhoons in the Philippines
PAGASA's Tropical Cyclone Intensity Scale[5][6]
Category Sustained winds
Supertyphoon (STY) >220 km/h
>119 knots
Typhoon (TY) 118–220 km/h
64–119 knots
Severe tropical storm (STS) 89–117 km/h
48–63 knots
Tropical storm (TS) 62–88 km/h
34–47 knots
Tropical depression (TD) ≤61 km/h
≤33 knots

The Philippines sit across the typhoon belt, making dangerous storms from July through October. Climate change exacerbates the situation with typhoons in the Philippines.[7] Typhoons are especially hazardous for northern and eastern Luzon and the Bicol and Eastern Visayas regions, but Manila gets devastated periodically as well. Bagyo is the Filipino term for any tropical cyclone in the Philippine Islands.[4] From the statistics gathered by PAGASA from 1948 to 2004, around an average of 28 storms and/or typhoons per year enter the PAR (Philippine Area of Responsibility) – the designated area assigned to PAGASA to monitor during weather disturbances. Those that made landfall or crossed the Philippines, the average was nine per year. In 1993, a record 19 typhoons made landfall in the country making it the most in one year. The fewest per year were 4 during the years 1955, 1958, 1992, and 1997.[8]

PAGASA categorises typhoons into five types according to wind speed. Once a tropical cyclone enters the PAR, regardless of strength, it is given a local name for identification purposes by the media, government, and the general public.[9]

Public Storm Warning System (PSWS)
PAGASA's
Tropical Cyclone Warning Signals (TCWS)[10][11]
Warning Signal Meaning
TCWS #1 winds of 30–60 km/h (20-37 mph)
are expected to occur within 36 hours
TCWS #2 winds of 61–120 km/h (38–73 mph)
are expected to occur within 24 hours
TCWS #3 winds of 121–170 km/h (74–105 mph)
are expected to occur within 18 hours
TCWS #4 winds of 171–220 km/h (106–137 mph)
are expected to occur within 12 hours
TCWS #5 winds greater than 220 km/h (137 mph)
are expected to occur within 12 hours

For the past ten years, the Philippines has experienced a number of extremely damaging tropical cyclones, particularly typhoons with more than 20 km/h (12 mph; 11 kn; 5.6 m/s) of sustained winds. Because of this, the Super Typhoon (STY) category with more than 220 km/h (140 mph; 120 kn; 61 m/s) maximum sustained winds was officially adopted by the PAGASA. However, according to different stakeholders, the extensive and devastating damages caused by strong typhoons such as Typhoon Haiyan (Yolanda) in 2013 made the four‑level warning system inadequate.

Strongest typhoons

Typhoon Haiyan (Yolanda)

The deadliest typhoon to impact the Philippines was Typhoon Haiyan, locally known as Yolanda, in November 2013, in which more than 6,300 lives were lost from its storm surges and powerful winds. Over 1,000 went missing and nearly 20,000 were injured. Winds reached 315 km/h (196 mph; 170 kn; 88 m/s) in one–minute sustained and may have been the strongest storm in history in terms of wind speeds as wind speeds before the 1970s were too high to record.

Typhoon Angela (Rosing)

Back in 1995, where Typhoon Angela, known as Rosing was an extremely catastrophic category 5 typhoon that made landfall in Catanduanes and made across Manila. Winds reached 290 km/h (180 mph) on one-minute sustain winds. Rosing took 936 lives and the most powerful typhoon that ever hit Metro Manila.

Typhoon Bopha (Pablo)

On late December 3, 2012, Typhoon Bopha or known as Pablo made landfall on Eastern Mindanao, damage was over US$1.04 billion by winds of 280 km/h (175 mph) on one-minute sustain winds. Typhoon Bopha was the most powerful typhoon ever hit Mindanao, killing 1,067 people and 834 people were missing. Most of the damage was caused by rushing storm surges and screaming winds.

Typhoon Megi (Juan)

Typhoon Megi (2010) was the strongest storm ever to make landfall in the country in terms of pressure.

It reached wind speeds of 295 km/h (185 mph) on one-minute sustained winds, killing 67 people and costing over US$700 million in damage.

Climate types
Four kinds of tropical sunshine (°C)
Four kinds of tropical rain (mm)

There are four recognized climate types in the Philippines, and they are based on the distribution of rainfall (See the Philippine Climate Map at the top).[lower-alpha 1] They are described as follows:[1]

  •  
 Type Ⅰ Two pronounced seasons: dry from November to April and wet during the rest of the year.
  •  
 Type Ⅱ No dry season with a pronounced rainfall from November to January.
  •  
 Type Ⅲ Seasons are not very pronounced, relatively dry from November to April, and wet during the rest of the year.
  •  
 Type Ⅳ Rainfall is more or less evenly distributed throughout the year.

Temperature

The average year-round temperature measured from all the weather stations in the Philippines, except Baguio, is 26.6 °C (79.9 °F). Cooler days are usually felt in the month of January with temperature averaging at 25.5 °C (77.9 °F) and the warmest days, in the month of May with a mean of 28.3 °C (82.9 °F).[1] Elevation factors significantly in the variation of temperature in the Philippines. In Baguio, with an elevation of 1,500 m (4,900 ft) above sea level, the mean average is 18.3 °C (64.9 °F) or cooler by about 4.3 °C (8 °F). In 1915, a one-year study was conducted by William H. Brown of the Philippine Journal of Science on top of Mount Banahaw at 2,100 m (6,900 ft) elevation. The mean temperature measured was 18.6 °C (65.5 °F), a difference of 10 °C (18 °F) from the lowland mean temperature.[16]

Humidity

Relative humidity is high in the Philippines. A high amount of moisture or vapor in the air makes hot temperatures feel hotter. This quantity of moisture is due to different factors – the extraordinary evaporation from the seas that surrounds the country on all sides, to the different prevailing winds in the different seasons of the year, and finally, to the abundant rains so common in a tropical country. The first may be considered as general causes of the great humidity, which is generally observed in all the islands throughout the year. The last two may influence the different degree of humidity for the different months of the year and for the different regions of the archipelago.[17]

Seasons

The climate of the country is divided into two main seasons:

  1. the rainy season, from June to the early part of October;
  2. the dry season, from the later part of October to May. The dry season may be subdivided further into (a) the cool dry season, from the later part of October to February; and (b) the hot dry season, from March to May.[1] The months of April and May, the hot and dry months when schools are on their long break between academic years, is referred to as summer while in most of the northern hemisphere those months are part of spring.
Months November–February March–May June–August September–October
Rainfall
Dry
Wet
Temperature
Cool
Hot
Season
Cool Dry
Hot Dry
Rainy

Notes
  1. This classification was first established by Coronas 1920, pp. 68–72 and then slightly modified by PAGASA (Flores & Balagot 1969; Kintanar 1984).
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References
  1. "Climate of the Philippines". Philippine Atmospheric, Geophysical and Astronomical Services Administration. Archived from the original on November 15, 2015. Retrieved November 26, 2015.
  2. Coronas 1920.
  3. Coronas 1920, p. 110.
  4. Glossary of Meteorology. Baguio. Retrieved on June 11, 2008.
  5. Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) (May 2015). "About Tropical Cyclones: Classification of Tropical Cyclones". PAGASA.
  6. Esperanza O. Cayanan (July 20, 2015). "The Philippines modified its Tropical Cyclone Warning System" (PDF). World Meteorological Organization (WMO).
  7. Overland, Indra et al. (2017) Impact of Climate Change on ASEAN International Affairs: Risk and Opportunity Multiplier, Norwegian Institute of International Affairs (NUPI) and Myanmar Institute of International and Strategic Studies (MISIS).
  8. Philippine Atmospheric, Geophysical and Astronomical Services Administration. "Tropical Cyclone Statistics Archived May 25, 2013, at the Wayback Machine". Retrieved on June 26, 2010.
  9. Atlantic Oceanographic and Meteorological Laboratory, Hurricane Research Division. "Frequently Asked Questions: What are the upcoming tropical cyclone names?". NOAA. Retrieved December 11, 2006.
  10. Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) (May 2015). "Public Storm Warning Signal". PAGASA.
  11. Esperanza O. Cayanan (July 20, 2015). "The Philippines modified its Tropical Cyclone Warning System" (PDF). World Meteorological Organization (WMO).
  12. "Climatological Information for Manila". AmbiWeb GmbH. Retrieved February 17, 2016.
  13. "Climatological Information for Borongan, Eastern Samar". AmbiWeb GmbH. Retrieved February 17, 2016.
  14. "Climatological Information for Cebu City". AmbiWeb GmbH. Retrieved February 17, 2016.
  15. "Climatological Information for General Santos". AmbiWeb GmbH. Retrieved February 17, 2016.
  16. Coronas 1920, p. 53.
  17. Coronas 1920, p. 125.

Sources
  • Flores, J. F.; Balagot, V. F. (1969). Arakawa, Hidetoshi (ed.). Ch. 3: Climate of the Philippines. World Survey of Climatology. Vol. 8: Climates of Northern and Eastern Asia. Elsevier. ISBN 978-0444407047.CS1 maint: ref=harv (link)
  • Kintanar, R. L. (1984). Climate of the Philippines. PAGASA.CS1 maint: ref=harv (link)
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