State weather bureau PAGASA also warns the public that more typhoons are possible in the last quarter of the year, due to La Niña
GOODBYE, SUMMER. PAGASA announces on May 24, 2016 that the Philippines is already shifting to the rainy season. File photo by Mark Cristino/Rappler
MANILA, Philippines – It's official: the rainy season has begun.
State weather bureau PAGASA announced on Tuesday, May 24, that the country is already shifting from the dry to the wet season.
In the past few days, PAGASA said there has been "widespread rainfall" in the country, signaling the shift.
The requirement before the onset of the rainy season can be declared is at least 5 days of rain generating a total amount of 25 millimeters (mm) of rainfall.
These 5 days must also include 3 straight days of at least 1 mm of rainfall.
PAGASA forecaster Benison Estareja told Rappler that these conditions will be fully met in the next few days, prompting the state weather bureau to already declare the beginning of the rainy season.
The rains in Mindanao are due to the Intertropical Convergence Zone (ITCZ), while other areas such as Metro Manila have been experiencing isolated thunderstorms.
Weather data also show that the southwest monsoon is now moving across the West Philippine Sea. It is expected to bring more rains to the western parts of Luzon and the Visayas in the coming days.
PAGASA expects 7 to 17tropical cyclones to hit the Philippines from May to October. The first one will be named Ambo.
In 2015, there were 15tropical cyclones. The last two – Nona and Onyok – were both in the Philippine Area of Responsibility at the same time in mid-December.
La Niña phenomenon
The state weather bureau also warned the country to brace for the La Niña phenomenon, which could gradually develop starting August.
Right now, the Philippines is still experiencing El Niño, which has triggered drought in parts of Mindanao. El Niño, which is already weakening, will end in July.
When La Niña kicks in, the Philippines would face the threat of more typhoons, particularly in the last quarter of 2016.
Estareja explained that typhoons during the period of La Niña will not necessarily be stronger, but their frequency is expected to increase.
The typhoons will also enhance the southwest monsoon, which would then bring floods and landslides.
PAGASA is calling on local government units and the public to prepare for the rainy season, as well as La Niña. – Rappler.com
Published 8:35 PM, May 24, 2016
Updated 8:35 PM, May 24, 2016
The Philippines has five types of climates: tropical rainforest, tropical savanna, tropical monsoon, 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. 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 cooler air from November to February. May is the warmest month, and January, the coolest.
Weather in the Philippines is monitored and managed by Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).
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 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, 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 millimetres (197 in) in the mountainous east coast section of the country, to less than 1,000 millimetres (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); followed by extraordinary drought from October 1911 to May 1912, so that the annual amount of those two years were hardly noticeable.
Main article: Typhoons in the Philippines
|Super Typhoon||≥119 knots|
|Severe Tropical Storm||48–63 knots|
|Tropical Storm||34–47 knots|
|Tropical Depression||≤33 knots|
The Philippines sit across the typhoon belt, making dangerous storms from July through October. These 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 to any tropical cyclone in the Philippine Islands. 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.
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.
Public Storm Warning System (PSWS)
winds of 30–60 km/h (20-37 mph) are expected to occur within 36 hours
winds of 61–120 km/h (38–73 mph) are expected to occur within 24 hours
winds of 121–170 km/h, (74–105 mph) are expected to occur within 18 hours.
winds of 171–220 km/h, (106–137 mph) are expected to occur within 12 hours.
winds of at least 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 Yolanda in 2013 made the four‑level warning system inadequate.
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.
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.
On late December 3, 2012, Typhoon Bopha or known as Pablo made landfall on Eastern Mindanao, damage was over 1.04 billion USD 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.
In terms of central pressure, Typhoon Megi (2010) measured 885 mb. This was the strongest storm ever to make landfall in terms of pressure.
It was 295 kph (185 mph) in terms of one-minute sustained winds, killing 67 people and costing over 700 million USD 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).[a] They are described as follows:
|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.|
The average year-round temperature measured from all the weather stations in the Philippines, except Baguio City, 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). Elevation factors significantly in the variation of temperature in the Philippines. In Baguio City, 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.
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.
The climate of the country is divided into two main seasons:
- the rainy season, from June to October;
- the dry season, from November to May. The dry season may be subdivided further into (a) the cool dry season, from November to February; and (b) the hot dry season, from March to May. 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.
- 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.