Dangerously hot: Batangas, Cavite sizzle at 45°C heat index
Warm and humid weather conditions persisted on Friday, April 30 as the heat indexes in Ambulong, Batangas and Sangley Pt., Cavite stations reached 45 degrees Celsius at around 2 p.m., based on the monitoring of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA).
Six other monitoring stations also recorded high heat indexes between 41 and 43 degrees Celsius on Friday afternoon.

These were in Butuan City, Agusan del Norte (43 degrees Celsius); Casiguran, Aurora (42 degrees Celsius); Dipolog, Zamboanga del Norte (42 degrees Celsius); Cotabato City, Maguindanao (41 degrees Celsius); NAIA Pasay City (41 degrees Celsius); and Zamboanga City, Zamboanga del Sur (41 degrees Celsius).
A heat index between 41℃ and 54℃ is under what the PAGASA considers as "danger" level due to the high likelihood of heat cramps and heat exhaustion.
Meanwhile, PAGASA's Science Garden monitoring station in Quezon City registered a heat index of 38 degrees Celsius at around 2 p.m.
A heat index between 32 and 40 degrees Celsius falls under "extreme caution" due to possible heat cramps and heat exhaustion while continuing activity could result in heatstroke.
Heat index is the measurement of how hot it feels when relative humidity is factored in with the actual air temperature.

The highest heat index so far in 2021 was recorded in Dagupan City, Pangasinan on April 6 at 49 degrees Celsius.
The warm and humid weather across most parts of the country could be attributed to the prevailing easterly winds originating from the Pacific Ocean.