Screengrab of the iHeatMap showing the heat index forecast for Taguig City in Metro Manila. (Photo Courtesy of DOST-PAGASA)
QUEZON CITY (PIA) – As the Philippines braces for extreme heat conditions, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) has launched an online monitoring guide that can help Filipinos make life-saving decisions to mitigate their exposure to health risks.
The online platform, called the Interactive Heat Index Mapping and Prediction or “iHeatMap,” provides access to accurate, real-time, and localized heat index data across the country.
Heat index primarily indicates the “feels-like” temperature or how hot it feels when the relative humidity is combined with actual air temperature. In the country where higher temperatures are recorded almost everyday, information about heat index is crucial for public health and safety.
PAGASA Administrator Nathaniel T. Servando underscored that iHeatMap is designed to empower Filipinos with the knowledge they need to take proactive measures to protect themselves from heat-related illnesses.
“iHeatMap empowers Filipinos with real-time, science-based heat index data — so they can make informed, timely, and potentially life-saving decisions,” said Servando.
Having a reliable source of heat index information also provides local government units with a vital metric to implement preventive measures and action plans to ensure the well-being of their communities during periods of extreme heat, such as the adjustment of class schedules in schools, rescheduling of road works, or granting heat breaks for field workers.
“It is a great example of how technology and science can work together for everyday public health and safety,” he added.
Key features
The iHeatMap can be accessed at the official website of DOST-PAGASA. It provides an interactive and user-friendly interface which allows users to conveniently check location-specific forecasts in just one click.
Real-time heat index data: The iHeatMap displays the current heat index data for various locations in real-time. Its high-resolution, gridded heat index information allows users to quickly assess the level of heat stress in their respective locality and the corresponding dangers.
Color-coded warnings: The online platform utilizes color-coded heat index categories for easy interpretation and measured response. Yellow indicates Caution (27-32°C), Yellow-Orange for Extreme Caution (33-41°C), Red-Orange for Danger (42-51°C), and Red for Extreme Danger (52°C and above).
The heat index map also integrates relevant health advisories per category. For instance, the yellow warning indicates that prolonged exposure may result in fatigue and heat cramps. The yellow-orange, on the other hand, signifies the possibility of experiencing heat cramps and heat exhaustion which can progress to heat stroke during sustained activity.
For the red-orange code, heat cramps and heat exhaustion are more likely to occur with continued exposure while red warning alerts that heat stroke is imminent.
Historical data and 2-day forecasts: The platform provides daily computed heat index including the specific time when the highest heat is expected. It also offers 2-day forecasts to allow users to anticipate potential heat hazards and implement heat safety measures in advance. In addition, users can review the heat index summary over the last five days to identify any significant increases or decreases in heat levels.
PAGASA, meanwhile, continues to advise the public to take precautions against heat-related emergencies for their safety.
“It is advisable to limit time spent outdoors, drink plenty of water, and avoid beverages such as tea, coffee, soda, and alcohol as these may cause dehydration due to frequent urination,” the state weather bureau advised.
“When outside, wearing hats, using umbrellas, and dressing in long-sleeved clothing can provide additional protection from the sun,” it added.
The iHeatMap is available from March to May 2025.
Heat index information from the online platform utilizes data from the European Centre for Medium-Range Weather Forecasts (ECMWF), an international research institute that produces 24/7 global numerical weather forecasts to contribute to the establishment of climate-resilient populations. (JMP/PIA-NCR)
