Instituto Portugues do Mar e Atmosfera - Homepage

  • Who we are | 
  • Where we are | 
  • Scientific Council | 
  • Research | 
  • eLibrary | 
  • ipma encyclopedia  | 
  • Contacts | 
  • Português
  • Weather
    • Weather forecast
    • 10 days and hourly forecast
    • Weather Warnings
    • Meteorological charts
    • Vertical profile
    • Satellite observations
    • Radar
    • Lightning
    • Solar Radiation
    • Online weather stations
    • World forecast
    • Tropical cyclones forecast
    • Report a meteorological phenomenon?
  • Seismic
    • Seismic maps
    • Shakemap
    • Felt an earthquake?
    • Moment Tensor
    • Networks
    • Bulletins
    • Projects
  • Sea
    • Beaches and ports
    • Marine forecast
    • Significant wave height
    • Sea peak period
    • Surface current
    • Sea surface temperature
    • Sea surface height
  • Climate
    • Climate Monitoring
    • Climate Normals
    • Daily monitoring
    • Long data series
    • Monthly monitoring
    • Drought
    • Greenhouse gases
    • Climate Extremes
    • Climate web portal
    • Climate Services
  • Bivalves
    • Bivalves - Situation point
    • Legislation and Documents
    • Production areas
    • Biotoxins
    • Phytoplankton
    • Contaminants Metals
    • Microbiology
    • Bivalves - historical
  • Fisheries
    • Disclosure
    • Projects
    • Fish management
    • ICES
  • Aeronautic
    • TAF and METAR
    • Selfbriefing
    • Know more
  • Agriculture
    • Soil Moist Index
    • Vegetation Health Index (VHI)
    • Fraction of Absorbed Radiation (FAPAR)
    • More information
    • Agroclimatic platform
  • Health
    • Ultra-violet index
    • Ozone
    • Pollen
  • Vessels
    • Framework
    • RV Mário Ruivo
    • RV Diplodus
    • Maris
    • Recife II
    • Cardium
  • Space
    • MSG satellite
  • Rural Fires
    • Mainland Rural Fire Danger
    • Madeira Rural Fire Danger
    • Reports Rural Fire Danger

News

  • Marine Ecosystem Accounts

    Workshop on the Value of the Portuguese Sea
    Fri Oct 24 09:00:00 UTC 2025
  • Students from the French Vocational School

    EPLEFPA Bréhoulou at EPPO
    Fri Oct 24 08:00:00 UTC 2025
  • Oceanic Marine Protected Areas

    Campaign to Madeira–Tore Complex
    Wed Oct 22 09:00:00 UTC 2025
  • More news
IPMA>Climate>Drought Observatory

PDSI Index (Palmer Drought Severity Index)

PDSI Index - Current situation - September 2025

De acordo com o índice PDSI no final de setembro, verificou-se um aumento da área em seca meteorológica moderada no interior da região Sul (distritos de Évora, Beja e Faro) e em alguns concelhos do vale do Tejo (distrito de Santarém). Na região Norte e litoral Centro observa-se no final do mês uma diminuição da área em seca meteorológica. Alguns concelhos dos distritos do Porto, Aveiro e Coimbra já não se encontram em seca meteorológica, devido aos valores de precipitação mais elevados que ocorreram no final do mês nestas zonas do território.

A distribuição percentual por classes do índice PDSI no território continental, no final de setembro é a seguinte:

  • 05.5% na classe normal,
  • 67.8% na classe de seca fraca e
  • 26.7% na classe de seca moderada.

Drought monitoring

  • Summary and about

Legend

PDSI Index (Palmer Drought Severity Index) was developed by Palmer (1965) and implemented and calibrated for mainland Portugal (Pires, 2003).

This index is based on the concept of the water balance taking into account data on the amount of precipitation, air temperature and available water capacity in the soil and allows the detection of periods of drought by classifying them in terms of intensity (weak, moderate, severe and extreme).

Table - Classification of the PDSI index for dry and rainy periods
Color legend PDSI Classes Description
greater than or equal to 4,0 Extreme rain Extreme rain
3,00 to 3,99 Severe rain Severe rain
2,00 to 2,99 Moderate rain Moderate rain
1,00 to 1,99 Weak rain Weak rain
-0,99 to 0,99 Normal Normal
-1,99 to -1,0 Weak drought Weak drought
-2,99 to -2,0 Moderate drought Moderate drought
-3,99 to -3,0 Severe drought Severe drought
less than or equal to -4,00 Extreme drought Extreme drought

Last 12 month evolution

 
 
  • Media

    • News
    • Communiqué
    • Lectures / workshops
    • YouTube
    • IPMA on Educast
  • Social network

    • Facebook
    • Facebook - Azores
    • Twitter
    • Instagram
  • Services

    • Products and services
    • RSS
    • Apps Android
    • Apps Apple
    • PDA
  • Information

    • Contact
    • Useful links
    • Research scholarship
    • EEAGrants projects
    • ECMWF
  • About site

    • Accessibility
    • Legal warnings
    • Site Map
  • Web projects

    • Observar
    • Subscriptions
    • Survey
    • E-learning
    • Shakemap
 
  • Apcer - A marca da Certificação
  • Lisboa:
        UTC:

    Copyright © Portuguese Institute for Sea and Atmosphere 2025
  • Ministério da Agricultura e Mar