IRON MOUNTAIN — A long-range forecast from the National Weather Service favors above-average temperatures in the Upper Peninsula this summer while the outlook is neutral on rainfall.

The Climate Predication Center sees a 45% chance of above-average temperatures through August and a 20% chance of below normal. The forecast comes as conditions in the central and eastern equatorial Pacific Ocean transition to a cooler phase, even as global sea surface temperatures remain high elsewhere.

The 2023-24 El Nino event, which helped fuel a spike in global temperatures, is showing signs of ending, the World Meteorological Organization reported Monday. The strong El Nino was a likely contributor to the record-breaking warmth experienced locally this past winter, climate experts say.

WMO now predicts at least a 60% chance of La Nina during July-September. La Nina, the flip side of El Nino, is the cooling of the central and eastern Pacific. In some regions, La Nina produces the opposite climate impacts to El Nino, although no two La Nina events are alike.

Globally, the past nine years have been the warmest on record even with the cooling influence of a multi-year La Nina from 2020 to early 2023, WMO said. El Nino, meanwhile, peaked in December 2023 as one of the five strongest on record.

“The end of El Nino does not mean a pause in long-term climate change, as our planet will continue to warm due to heat-trapping greenhouse gases,” WMO Deputy Secretary-General Ko Barrett said in WMO’s news release.

The latest Global Seasonal Climate Update from WMO says that widespread above-normal sea-surface temperatures in all areas are expected to persist outside the near-equatorial eastern Pacific Ocean. “There is therefore widespread prediction of above-normal temperatures over almost all land areas,” WMO said.

NWS forecaster Dan Collins said the summer outlook for the U.S. is influenced by observations of warming over the past decade. “The temperature outlooks for the next two seasons, through summer into early autumn, favor above-normal temperatures across the entire continental U.S., driven by strong decadal temperature trends in these seasons, and lesser impacts of a potential La Nina,” he said.

Temperatures in May at Iron Mountain-Kingsford averaged 56.2 degrees, which was about 2 degrees above normal. The highest reading was 83 degrees reported on May 19 and the lowest was 32 degrees on May 10.

Temperatures have averaged above normal every month of 2024, with the biggest divergence in February, when the average reading of 29.3 degrees was 12.1 degrees above normal, NWS statistics show.

May was wet, with 5.11 inches of rain measured at the Iron Mountain-Kingsford Wastewater Treatment Plant observation site. That was nearly 2 inches above the mean since observations began in the early 1900s.

Spring has been generally wet across the Midwest, erasing a drought that took hold in winter. According to the U.S. Drought Monitor, dry conditions are absent across 93% of Wisconsin, compared with just 10% in early March. In Michigan, 93% of the state is free of drought, compared with just 9% three months ago.

Currently, the only area of drought in the U.P. is near Lake Superior in Gogebic and Ontonagon counties.