SEATTLE — This story was originally published on MyNorthwest.com
The National Oceanic and Atmospheric Administration (NOAA) just released its annual Global Temperature and Precipitation Analysis for 2025, and the results continue recent trends.
The report highlighted that last year was the third-warmest year globally on record, just behind 2023 as the second warmest and 2024, the warmest ever. The analysis reviews weather and ocean data going back to 1850.
The report noted that the past decade was the warmest ever on record, continuing a trend going back to the 1960s. This past decade was 2.41 degrees Fahrenheit warmer than the 1850-1900 average, when the industrial age got underway in the late 1800s.
Western Washington was also a part of this overall warming trend. In fact, December at Seattle-Tacoma International Airport (SEA) was the third-warmest on record. Globally, 2025 was nearly two degrees Fahrenheit above the 20th-century temperature average.
The atmosphere is not only warmer than ever, but the oceans are also warmer. In fact, the report noted that upper-ocean heat content reached an all-time record in 2025. The oceans store about 90 percent of the globe’s excess heat.
Impacts
The warmer atmosphere and oceans have a great number of impacts. The biggest impact is that greater heat adds more energy to storms. One local example was the November 2024 bomb cyclone strong wind event.
Another significant impact that studies have revealed is that the warmer atmosphere can hold at least 10% more moisture. That greater amount of moisture leads to heavier rainfall, resulting in more floods and flash floods.
Another impact concerns the reduced snow cover. The report noted that the 2025 Northern Hemisphere snow cover was the third-lowest on record.
Climatologists across the Western U.S. are expressing concern that this winter’s limited mountain snowpack from the Pacific Northwest to California and the Rockies will limit water supplies later this year and accelerate dry conditions that are favorable for wildfires.
Those limited water supplies can domino to other key issues, such as the production of hydroelectric power, agriculture, consumer water supplies, fish, and more. The warmer atmosphere also means average mountain snow levels are higher, with rain falling in lower elevations. Higher mountain terrain also has less real estate, meaning that overall, there is less snow available to melt and run off during spring, summer, and fall, again reducing available water supplies.
In December, the Washington Cascades and Olympics had limited snow on the ground when a series of warm, wet rainfall events arrived. With essentially no snow in place, the heavy amounts of rainfall led to widespread significant flooding across much of the region.
Cooler weather finally arrived late in December, allowing mountain snows to pile up. This past weekend, another warm, wet weather system dumped more rain. Yet this time, the mountain snowpack soaked up the rain and sharply limited the runoff in the rivers, resulting in far more limited rises in the area rivers. Having a mountain snowpack plays a key role in helping limit river flooding.
Ocean Impacts
The warm oceans also have their impacts. The NOAA report highlighted that global ice extent last year was the second lowest on record. In December 2025, in both the Arctic and the Antarctic, overall sea ice was the second lowest ever for the month. As a result, sea levels across much of the globe continued to inch up during 2025.
The greater heat in the oceans helped trigger 101 named tropical storms around the globe, above the 1981-2020 average of 88 named storms. 52 of those grew to hurricane force, with five reaching the top category (5) with sustained winds of at least 157 mph on the Saffir-Simpson hurricane wind scale.
What Lies Ahead?
Quite likely, this warming trend in both the atmosphere and the oceans will continue, helping to drive stronger storms, more wildfires, and less snow during the winter season. Preparedness for the overall results is critical for all communities, not only in Western Washington, but across the nation and around the world.
Ted Buehner is the KIRO Newsradio meteorologist. Follow him on X and Bluesky. Read more of his stories here.
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