5. ◈ Weather is the mix of events that happen
each day in our atmosphere. Weather is
different in different parts of the world and
changes over minutes, hours, days and
weeks. Most weather happens in the
troposphere, the part of Earth's atmosphere
that is closest to the ground.
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9. Climate in the Philippines
◈ Tropical and maritime. It is characterized by
relatively high temperature, high humidity,
and abundant rainfall. It is similar in many
respects to the climate the countries of the
Central America. Temperature, humidity and
rainfall, which are discussed hereunder, are
the most important element’s of the
country’s weather and climate. 9
10. Temperature
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Temperature is a physical
quantity that expresses hot
and cold. It is the
manifestation of thermal
energy, present in all matter,
which is the source of the
occurrence of heat, a flow of
energy, when a body is in
contact with another that is
colder or hotter.
Temperature is measured
with a thermometer.
11. ◈ 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). Elevation factors
significantly in the variation of temperature in
the Philippines
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12. ◈ 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
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13. ◈ The difference between the mean annual
temperature of the southernmost station in
Zamboanga and that of the northermost
station in Laoag is insignificant. In other
words, there is essentially no difference in the
mean annual temperature of places in Luzon,
Visayas or Mindanao measured at or near sea
level.
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14. Humidity
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Temperature is a physical
quantity that expresses hot
and cold. It is the
manifestation of thermal
energy, present in all matter,
which is the source of the
occurrence of heat, a flow of
energy, when a body is in
contact with another that is
colder or hotter.
Temperature is measured
with a thermometer.
15. ◈ 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
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16. ◈ 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
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18. ◈ The mean annual rainfall of the Philippines
varies from 965 to 4,064 millimeters
annually. Baguio City, eastern Samar, and
eastern Surigao receive the greatest amount
of rainfall while the southern portion of
Cotabato receives the least amount of rain.
At General Santos City in Cotabato, the
average annual rainfall is only 978
millimeters. 18
20. ◈ Using temperature and rainfall as bases, the
climate of the country can be divided into
two major seasons: (1) the rainy season,
from June to November; and (2) the dry
season, from December to May. The dry
season may be subdivided further into (a) the
cool dry season, from December to
February; and (b) the hot dry season, from
March to May. 20
22. ◈ In the Philippines, Amihan and
Habagat refer to the two kinds of winds
and seasons that occur in the country every
year.
Amihan is known as the Northeast monsoon
while Habagat is known as the Southwest
monsoon.
A monsoon is a seasonal rain and wind
pattern. "Monsoon" is from the Arabic word,
"mawsim" which means season.
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23. ◈ A switch in wind direction is the primary
indicator for the change between one
monsoon to the other. It usually takes place
during nighttime.
At some periods, the two monsoons switch
several times before settling into a pattern
for the season.
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26. ◈ Based on the distribution of rainfall, four
climate types are recognized, which are
described as follows:
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27. ◈ Typhoons have a great influence on the
climate and weather conditions of the
Philippines. A great portion of the rainfall,
humidity and cloudiness are due to the
influence of typhoons. They generally
originate in the region of the Marianas and
Caroline Islands of the Pacific Ocean which
have the same latitudinal location as
Mindanao. 27
28. ◈ Their movements follow a northwesterly
direction, sparing Mindanao from being
directly hit by majorty of the typhoons that
cross the country. This makes the southern
Philippines very desirable for agriculture and
industrial development.
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29. 29
Tropical Cyclone Wind Signal #1
WINDS: 30-60 kph may be expected in at least 36 hr.
SEA CONDITIONS (Open Sea)
Wave Height: 1.25-4.0 meters
30. DAMAGE TO STRUCTURE:
• Very light or no damage to high risk structures,
• Light to medium and low risk structures
• Slight damage to some houses of very light materials or makeshift
structures in exposed communities.
DAMAGE TO VEGETATION:
• Some banana plants are tilted, a few downed and leaves are generally
damaged.
• Twigs of small trees may be broken.
• Rice crops, however, may suffer significant damage when it is in its
flowering stage.
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31. 31
Tropical Cyclone Wind Signal #2
WINDS: 61-120 kph may be expected in at least 24 hr
SEA CONDITIONS (Open Sea)
Wave Height:4.1-14.0 m
Storm surge possible at coastal areas.
32. DAMAGE TO STRUCTURE:
• Light to Moderate damage to high risk structures;
• Very light to light damage to medium-risk structures;
• No damage to very light damage to low risk structures.
• Unshielded, old dilapidated schoolhouses, makeshift shanties, and other structures of light
materials are partially damaged or unroofed.
• Some old galvanized iron (G.I.) roofs may be peeled or blown off.
• Some wooden, old electric posts are tilted or downed. Some damage to poorly constructed
signs/billboards.
DAMAGE TO VEGETATION:
• Most banana plants, a few mango trees, ipil-ipiland similar trees are downed or broken.
• Some coconut trees may be tilted with few others broken.
• Rice and corn may be adversely affected.
• Considerable damage to shrubbery and trees with some heavy-foliaged trees blown down.
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33. 33
Tropical Cyclone Wind Signal #3
WINDS: 121-170 kph may be expected in at least 18 hr.
SEA CONDITIONS (Open Sea)
Wave Height: > 14.0 meters
Storm surge possible at coastal.
34. DAMAGE TO STRUCTURE:
• Heavy damage to high–risk structures;
• Moderate damage to medium-risk structures;
• Light damage to low-risk structures.
• Increasing damage to old, dilapidated residential structures and houses of light materials
(up to 50% in a community).
• Houses of medium strength materials (old, timber or mixed timber-CHB structures, usually
with G.I. roofing), some warehouses or bodega-type structures are unroofed
DAMAGE TO VEGETATION:
• Almost all banana plants are downed, some big trees (acacia, mango, etc.) are broken or
uprooted,
• Dwarf-type or hybrid coconut trees are tilted or downed.
• Considerable damage to shrubbery and trees with heavy foliage blown off; some large
trees blown down.
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35. 35
Tropical Cyclone Wind Signal #4
WINDS: 171-220 kph may be expected in at least 12 hr
SEA CONDITIONS (Open Sea)
Wave Height: more than 14.0 meters
Storm surge 2-3m possible at coastal areas.
36. DAMAGE TO STRUCTURE:
• Very heavy damage to high –risk structures.
• Heavy damage to medium risk structures;
• Moderate damage to low-risk structures.
• Considerable damage to structures of light materials (up to 75% are totally and partially
destroyed); complete roof structure failures.
• Many houses of medium-built materials are unroofed, some with collapsed walls; extensive damage
to doors and windows.
• A few houses of first-class materials are partially damaged.
• All signs/billboards are blown down.
DAMAGE TO VEGETATION:
• There is almost total damage to banana plantation,
• most mango trees, ipil-ipil land similar types of large trees are downed or broken.
• Coconut plantation may suffer extensive damage.
• Rice and corn plantation may suffer severe losses
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37. 37
Tropical Cyclone Wind Signal #5
WINDS: > 220 kph may be expected in at least 12 hr
A Super Typhoon will affect the locality.
SEA CONDITIONS (Open Sea)
Wave Height: more than 14.0 m
Storm surge more than 3 meters possible at coastal areas
38. DAMAGE TO STRUCTURE:
• Widespread damage to high-risk structures. Very heavy damage to medium-risk structures
• Heavy damage to low-risk structures;
• Almost total damage to structures of light in highly exposed coastal areas.
• Complete roof failure on many residences and industrial buildings. Severe and extensive window
and door damage
• Most residential and institutional buildings of mixed construction may be severely damaged.
• Electrical power distribution and communication services severely disrupted.
• All signs/billboards blown
DAMAGE TO VEGETATION:
• Total damage to banana plantation
• Most tall trees are broken, uprooted or defoliated;
• Coconut trees are stooped, broken or uprooted.
• Few plants and trees survived
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