The Mass in Tacloban was shortened because of an approaching typhoon that had sustained winds of 80 mph and higher gusts.
A throng gathered at the Tacloban airport to greet the Pope when he arrived at about 9 a.m. local time (8 p.m. ET.)
The Mass began nearby about half an hour after he landed. Wind rustled the hood on the pontiff's slicker as he spoke to a crowd clad in raincoats.
Tacloban is still recovering from the 2013 disaster of Super Typhoon Haiyan,
described as perhaps the strongest storm ever recorded with 195 mph sustained winds that killed 6,300 people nationwide.
Typhoon Mekkhala was upgraded from a tropical storm and should make landfall in the Philippines at about noon, about an hour after the Mass concluded, just northeast of Tacloban, said CNN meteorologist Sean Morris.
The forecast track has shifted slightly northward with the center of the storm expected to pass north of Tacloban.
Another typhoon was headed for the same general area in the Philippines early Saturday, the Joint Typhoon Warning Center said.
Wet, gusty forecast
Typhoon Mekkhala, which is called Typhoon Amang in the Philippines, was arriving on the island of eastern Samar -- a site about 50 miles from where the Pope was in Tacloban.
Just two weeks ago, a tropical storm struck Tacloban and surrounding area, causing a commercial passenger plane to slide off the runway while landing at the Tacloban airport, CNN meteorologist Brandon Miller said. Tropical Storm Jiangmi, renamed Seniang in the Philippines, killed 54 people in landslides and flash floods in that region, CNN affiliate ABS-CBN reported.
During the Pope's visit to Tacloban, he will have lunch with survivors of the 2013 Typhoon Haiyan, renamed Typhoon Yolanda in that country. That typhoon displaced 918,000 families nationwide, the government says.
Francis is also to bless the Pope Francis Centre for the Poor and will meet with clergy and more typhoon survivors in the cathedral in Palo.
The Pope is expected to fly out of Tacloban at 5 p.m. Saturday (4 a.m. Saturday ET).
"At that point, they're still in the teeth of the storm. So not only is getting in a challenge, but also getting out," Miller said.
Sunday Mass in Manila
The Pontiff is also scheduled to perform an outdoor Mass in Manila on Sunday before millions of Filipinos, Miller said.
By then, the storm should weaken to a tropical depression, and its center should be about 109 miles south of the Pope, Miller said. Still, the storm is capable of delivering its heaviest rainfall at that distance, and Manila could face gusty winds and significant rain during the Mass, Miller added.
The Pope's trip to Asian isles began Tuesday in Sri Lanka, and he landed in the Philippines on Friday.
On Friday, Francis met with President Benigno Aquino, and the Pontiff urged the political leader to reject corruption and promote "honesty, integrity and commitment to the common good," the Vatican said. He also spoke of "the moral imperative of ensuring social justice and respect for human dignity," according to a copy of his remarks provided by the Vatican.
"Here in the Philippines, countless families are still suffering from the effects of natural disasters. The economic situation has caused families to be separated by migration and the search for employment, and financial problems strain many households. While all too many people live in dire poverty, others are caught up in materialism and lifestyles which are destructive of family life and the most basic demands of Christian morality," the Pope said in other remarks.
The Pope will end his tour Monday, when he will leave Manila for Rome.