BAGHDAD — Record-shattering temperatures this summer have scorched countries from Morocco to Saudi Arabia and beyond, as climate experts warn that the severe weather could be a harbinger of worse to come.

In coming decades, U.N. officials and climate scientists predict that the mushrooming populations of the Middle East and North Africa will face extreme water scarcity, temperatures almost too hot for human survival and other consequences of global warming.

If that happens, conflicts and refugee crises far greater than those now underway are probable, said Adel Abdellatif, a senior adviser at the U.N. Development Program’s Regional Bureau for Arab States who has worked on studies about the effect of climate change on the region.

“This incredible weather shows that climate change is already taking a toll now and that it is — by far — one of the biggest challenges ever faced by this region,” he said.

These countries have grappled with remarkably warm summers in recent years, but this year has been particularly brutal.

Parts of the United Arab Emirates and Iran experienced a heat index — a measurement that factors in humidity as well as temperature — that soared to 140 degrees in July, and Jiddah, Saudi Arabia, recorded an all-time high temperature of nearly 126 degrees. Southern Morocco’s relatively cooler climate suddenly sizzled last month, with temperatures surging to highs between 109 and 116 degrees. In May, record-breaking temperatures in Israel led to a surge in ­heat-related illnesses.

Temperatures in Kuwait and Iraq startled observers. On July 22, the mercury climbed to 129 degrees in the southern Iraqi city of Basra. A day earlier, it reached 129.2 in Mitribah, Kuwait. If confirmed by the World Meteorological Organization, the two temperatures would be the hottest ever recorded in the Eastern Hemisphere.

The bad news isn’t over, either. Iraq’s heat wave is expected to continue this week.

Stepping outside is like “walking into a fire,” said Zainab Guman, a 26-year-old university student who lives in Basra. “It’s like everything on your body — your skin, your eyes, your nose — starts to burn,” she said.