Could the same weather pattern that’s causing the balmy pre-Christmas weather in the East Coast and Midwest of the U.S. also be responsible for a punishing drought in southern Africa on the opposite side of the globe?

Scientists say yes—and they are pointing the finger at one of the most potent El Niño systems every recorded in the Pacific Ocean. The large pool of unusually warm water in the Pacific—perhaps the most extreme in 75 years—is forcing changes in normal weather patterns in the US, where it is keeping cold winter air firmly bottled up in the Arctic.

El Niño’s reach is also being felt in the sun-baked farmlands of rural Zimbabwe, Malawi and South Africa, where rains that usually start in October or November have simply not materialized this year.

Millions could suffer from famine if the pattern holds through the first few months of 2016 — as forecasters says it almost certainly will.

“Southern Africa is a particular and obvious concern,” said Maxx Dilley, director of the Climate Prediction and Adaptation division at the World Meteorological Organization. “A canonical effect of El Niño is drought in that part of Africa.”

Experts say this year’s El Niño is on par with the 1982-83 and 1997-98 seasons, which were the most extreme on record dating back to about 1950.

In the rural Madikwe district of South Africa, villagers are already praying for divine intervention.

“God, give us rain because we have a big problem,” Josephine Motsoasele told a gathering of 30 people, according to Agence-France Presse. “We can’t do anything.”

Why exactly does El Niño—which is named after Jesus because South American fisherman first noticed it around Christmas—have such a strong effect on Africa?
Scientists say the warm water of El Niño disrupts the powerful Pacific trade winds that flow from east to west and feed moisture into the tropical islands of Indonesia. That makes the archipelago cooler and drier than usual and in turn disrupts normal seasonal wind and current patterns in the Indian Ocean.

“The Pacific is so big and the area of warm water is so large that there is a shift in the circulation pattern around the globe,” said Wassila Mamadou Thiaw, a senior meteorologist with the U.S. National Oceanic and Atmospheric Agency (NOAA).
Off the east African coast, normal wind and current patterns tend to drive bands of warm water and moisture to the south during the southern hemisphere spring and summer. When El Niño is in effect, there is less moisture in general and warm currents and the rains they bring sometimes stay closer to the equator, depriving southern Africa of that moisture.

That pattern can lead to heavy rainfall in East Africa and the danger of flooding in Uganda, South Sudan, parts of Kenya and the Horn of Africa.

The impact on southern Africa is potentially much more dangerous because the region is semi-arid and relies on rains during the southern summer to produce staple crops, especially maize. Take away those rains, and millions of subsistence farmers will face starvation.

One reason for some hope is that El Niño does not always bring season-long drought in southern Africa — and in fact the 1997-98 season produced close to normal rains in the region despite that year’s record El Niño.

The Famine Early Warning System, a U.S.-government multiagency group, predicts up to 2.8 million people could face acute food shortages in Malawi alone. The maize harvest in Zimbabwe will be cut in half. UNICEF says 11 million children could go hungry.

South Africa, the economic engine and breadbasket of the region, is already warning of widespread crop failures.

Could global warming be feeding the climate chaos? Experts say it’s too early to draw a direct link between climate change and El Niño, which occurs naturally every few years.
But they do say that climate extremes are becoming more frequent and unpredictable, making El Niño potentially even more destructive.

“The term that’s often used is that it’s like a system on steroids,” said Nathan Moore, an assistant professor at Michigan State University who is an expert on the impact of climate change on Africa.

Sign up for the Quartz Africa Weekly Brief — the most important and interesting news from across the continent, in your inbox.