Gale Warning
Issued at: 5:00 PM TODAY , 21 August 2018
Gale Warning # 2

Gale Warning in PDF file

Dams Water Level Update
As of 6 AM, 26 SEPTEMBER 2017

General Flood Advisories - Regional
Issued as of 7AM 07 August 2017

Daily Basin Hydrological Forecast
Issued 21 FEBRUARY 2017

Monthly Climate Assessment and Outlook

Issued: 05 June 2017

Monthly Rainfall Forecast
RAINFALL FORECAST  (October 2017 - March 2018) 
UPDATED: 20 September 2017 (next update October 2017)

Regional Rainfall Forecast
Issued: 20 September 2017
Valid for: October 2017 - March 2018
Farm Weather Forecast and Advisories
ISSUED              : 8AM, THURSDAY, SEPTEMBER 7, 2017
FWFA:  N0. 17-251

Ten-Day Regional Agri-Weather Information
DEKAD NO. 25 SEPTEMBER 1-10, 2017

The weather systems that will affect the whole country are southwest monsoon, intertropical convergence zone (ITCZ) and low pressure area (LPA).
Seasonal Climate Outlook
Issued:  06 July 2017
FOR July - December 2017

Astronomical Diary
Issued for July 2018
A Total Lunar Eclipse will occur on July 28 and will be visible in the Philippines.

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 Impact Assessment for Agriculture full document

     The Impact Assessment and Applications Section (IAAS) of Climatology and Agrometeorology Division (CAD) regularly issue this monthly/bulletin which will provide users such as food security managers, economic policy makers, agricultural statisticians and agricultural extension officials with qualitative information on the current and potential effects of climate and weather variability on rainfed crops, particularly rice and corn. This bulletin, entitled “Climate Impact Assessment for Agriculture in the Philippines”, represents a method for converting meteorological data into economic information that can be used as supplement to information from other available sources.

    For example, an agricultural statistician or economist involved in crop production and yield forecast problems can combine the assessment with analysis from area survey results, reports on the occurrence of pests and diseases, farmers’ reports and other data sources.

  The impact assessments are based on agroclimatic indices derived from historical rainfall data recorded for the period 1951 to the present. The indices, expressed in raw values percent of normals and percentile ranks, together with real time meteorological data (monthly rainfall, in percent of normal), percent of normal cumulative rainfall, as well as the occurrence of significant event such as typhoons, floods and droughts are the tools used in the assessment of crop performance. Crop reports from PAGASA field stations are also helpful.

The narrative impact assessment included in the bulletin depicts the regional performance of upland, 1st lowland and 2nd lowland palay; and dry and wet season corn crops, depending on the period or the season. Tabulated values of normal rainfall and generalized monsoon and yield moisture indices are provided for ready reference. Spatial analysis of rainfall, percent of normal rainfall and the generalized monsoon indices in percentile ranks are also presented on maps to help users visualize any unusual weather occurring during the period. The generalized monsoon indices in particular, are drought indicators; hence, the tables (see Appendices) together with the threshold values can be used in assessing drought impact, if there are any. It also helps assess any probable crop failure.

It is hoped therefore that this bulletin would help provide the decision-makers, planners and economist with timely and reliable early warning/information on climatic impact including the potential for subsistence food shortfalls, thereby enabling them to plan alternate cropping, if possible, food assistance strategies/mitigation measures to reduce the adverse impact of climate and eventually improve disaster preparedness.

     Impact assessment for other principal crops such as sugarcane and coconut, for energy and for water resources management, are from time to time will be included in the forthcoming issues of this bulletin.

  The IAAS of CAD will appreciate suggestions/comments from end-users and interested parties for the improvement of this bulletin.

Definition of Terms

The Generalized Monsoon Index (GMI) helps determine the performance of the rains during the season and serves as a good indicator of potential irrigation supplies. It is a tool used to assess rainfed crops.

The GMI for the southwest monsoon (GMIsw) in an area during June to September is defined as follows:
GMIsw = W6P6 + W7P7 + W8P8 + W9P9

The GMI for the northeast monsoon (GMIne) in an area during October to January is defined as:
GMIne = W10P10 + W11P11 + W12P12 + W1P1
W = weight coefficient of monthly rainfall for the season;
P = rainfall amount in the ith month
(i = 1 for January, 2 = for February, etc.)

The Yield Moisture Index (YMI) is a simple index that helps the users assess agroclimatic crop conditions during the crop season. The YMI for a particular crop is defined as follows:
n YMI =  [Pi Ki] i
i = crop stage (1 = planting/transplanting,
2 = vegetative, 3 = flowering, 4 = maturity, etc.)
n = total no. of crop stages;
P = rainfall during the ith crop stage; and
K = appropriate crop coefficient for the ith crop stage.
Tentatively, the threshold values of categories of indices for interpretation being adopted for both YMI and GMI are as follows:

> 80 Potential for flood damage
41 - 80 Near normal to above-normal crop condition
21 - 40 Moderate drought impact with reduced yield
11 - 20 Drought impact with major yield losses
< 10 Severe drought impact with crop failure and potential food shortages




      Harvesting of July-planted lowland palay had just begun in most parts of the country. Good to normal yield is expected in CAR, Ilocos Region, Zambales, Tayabas, Ambulong, MIMAROPA, Bicol region, Bohol, Mactan, Catbalogan, Tacloban, Northern Mindanao, and ARMM.  In contrary, below normal yield may be anticipated in Cagayan Valley, Panay Island, and Dumaguete. Meanwhile, in some parts of the country sun drying and rice stocking activities is still in progress.

        Assessment of rainfall for the month of October showed that near to above normal rainfall conditions were experienced in most parts of the country, except in Benguet, Ifugao, La Union, Pangasinan, Nueva Ecija, Quirino, and Nueva Vizcaya which experienced below normal rainfall conditions. 

        The weather systems that affected the country during the month were the inter-tropical convergence zone (ITCZ), southwest (SW) monsoon, low pressure areas (LPAs), thunderstorms, northeast (NE) monsoon and the passage of three (3) tropical cyclones (TCs), namely:  Severe Tropical Storm (STS) “Odette” (October 11-14), Typhoon (TY) “Paolo” (October 16-21), and Severe Tropical Storm (STS) “Quedan” (October 25-28). Among these 3 TCs, only STS “Odette” directly hit the country.  STS “Odette” made landfall over Sta. Ana, Cagayan and brought moderate to heavy rains in the western section of the country, including Metro Manila.  It caused flooding and landslides over regions I, II, Cordillera Autonomous Region (CAR) and IV-B, based on the report of the National Disaster Risk Reduction and Management Council (NDRRMC).

REGION I (Ilocos Region)

     Harvesting of late-planted lowland palay had just begun across the region; near normal to normal yield is anticipated due to the sufficient moisture available from planting to maturity.

CAR (Cordillera Autonomous Region)
     Harvesting of late-planted lowland 1st palay now started; good to normal yield is expected, due to adequate moisture and normal conditions experienced by the crops throughout the entire growing season.

REGION II ( Cagayan Valley)
     Below normal yield is anticipated for the harvestable, July-planted lowland palay due to moisture stress experienced by the crops during the critical stage of growth and development.

REGION III (Central Luzon)

      Harvesting of July-planted lowland palay had just started all over the region; near normal to normal yield is estimated in Zambales because crops experienced sufficient moisture from planting to maturity.  On the other hand, in Cabanatuan, inadequate moisture supply during the month led to a below normal yield for the maturing crops.


      Harvesting of July-planted lowland palay in Ambulong and Tayabas had just begun. Near normal to above normal yield is anticipated in those areas because of the significantly adequate rainfall experienced by the crops in the entire growing season.


      Ample amount of moisture as well as sufficient sunshine received in the last decade of the month favored the harvestable, July-planted lowland palay across the region; good to normal yield is anticipated.

REGION V  (Bicol Region)  

    Harvesting of July-planted lowland palay commences. Yield is expected to be near normal to normal due to good weather and sufficient moisture experienced by the crops for the entire growing season.

REGION VI (Western Visayas) 

      Harvesting of late-planted lowland had just begun across the region. Yield is anticipated to be below normal because of moisture stress experienced by the crops during its critical stage of growth and development.

REGION VII (Central Visayas)

     Harvesting of July-planted lowland palay all over the region commences; yield is expected to be near normal to above normal due to the sufficient moisture from the planting to maturity stages. However, in Dumaguete, below normal yield is probable because in that area crops experienced moisture stress during the critical stage of growth.

REGION VIII (Eastern Visayas)
     Harvesting of July-planted lowland palay in Eastern Visayas is now in progress. Good to near normal yield is expected because crops experienced insufficient moisture during the vegetative stage, although the crops recovered in the last stages of growth and development.

 REGION IX (Zamboanga Peninsula)

      In Zamboanga del sur, planting of lowland palay is totally hampered because of very low rainfall received in that particular area last July, that is why no harvest will be expected this season.

REGION  X (Northern Mindanao)

    Harvesting of July-planted lowland palay had just begun. Near normal to above normal yield is expected because crops experienced normal crop conditions in the entire growing season. 

REGION XI (Davao Region)

    Sun drying and rice stocking activities for the late-planted upland palay are in their final stages.


    Due to the inadequacy of the required moisture for planting activities in the region, farming activities are all hampered in the area, hence, no harvest is expected for the season.


    Post-harvesting activities for the late-planted lowland palay had just begun all over the region. Sun drying and rice stocking activities shall follow.

ARMM ((Autonomous Region of Muslim  Mindanao)

     Harvesting of July-planted lowland palay has started in most parts of the region. Good yield may be expected this season because crops have recovered from previous stressed conditions.


For Particulars, please contact:

Impact Assessment and Applications Section (IAAS)
Climatology and Agrometeorology Division (CAD)
Telefax No.: 434-58-82



It has come to the attention of the Office of the Administrator of PAGASA that a certain person has been using the name of Dr. Vicente B. Malano to solicit money from the contractors of PAGASA.

Dr. Malano wishes to inform the public that he has not authorized anyone to solicit money on his behalf and to warn everyone against dealing with unscrupulous activities of certain individuals.

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Proof has been furnished by means of an audit that the requirements of ISO 9001:2008 are met.

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