The easterlies or the warm winds coming from the Pacific Ocean will be the dominant weather system that will bring warm and humid weather conditions over the country on Sunday, May 23.
The Philippine Atmospheric, Geophysical and Astronomical Services Administration (PAGASA) said Metro Manila and the rest of the country will be partly cloudy to cloudy in the morning with isolated rain showers or thunderstorms mostly in the afternoon or evening.

The prevalence of warm and humid weather conditions has continued to push the heat index values above 40 degrees Celsius (°C) in 14 areas on Saturday, May 22.
The heat index is the measurement of how hot it feels when relative humidity is factored in with the actual air temperature.
PAGASA's monitoring showed the following areas registering the top 14 heat index values on Saturday.
Ambulong, Batangas (45°C, 2 p.m.)
Aparri, Cagayan (44°C, 11 a.m.)
Dipolog, Zamboanga del Norte (44°C, 2 p.m.)
Dagupan City, Pangasinan (43°C, 11 a.m.)
Tuguegarao City, Cagayan (43°C, 12 p.m.)
Itbayat, Batanes (42°C, 2 p.m.)
Ninoy Aquino International Airport, Pasay City (42°C, 12 p.m.)
Sangley Point, Cavite (42°C, 11 a.m.)
Clark Airport, Pampanga (41°C, 2 p.m.)
Davao City, Davao del Sur (41°C, 12 p.m.)
Laoag City, Ilocos Norte (41°C, 11 a.m.)
Port Area, Manila (41°C, 2 p.m.)
Science Garden, Quezon City (41°C, 2 p.m.)
Sinait, Ilocos Sur (41°C, 2 p.m.)
A heat index above 40℃ is considered "dangerous" due to the high likelihood of heat cramps and heat exhaustion.
So far, the highest heat index in 2021 was registered in Dagupan City, Pangasinan at 53℃ on May 14.