The perfect weather day could happen less often in the future.

The mild weather most people prefer, sunny with temperatures between 64 and 86 degrees Fahrenheit, will yield to more extreme weather in many parts of the globe, according to a new study published today.

The study, published in the journal Climatic Change, found that the global number of mild weather days could decline by up to 13 percent by the end of the century as a result of climate change. The current global average of 74 so-called perfect weather days will drop by four in 2035 and by 10 in 2081 to 2100, researchers found.

Climate change research often focuses on extremes. However, the goal of the National Oceanic and Atmospheric Administration study was to look at something less extreme, said Karin van der Wiel, a researcher at NOAA's Geophysical Fluid Dynamics Laboratory and the study's lead author.

“Extreme weather is difficult to relate to because it may happen only once in your lifetime,” she said. “We took a different approach here and studied a positive meteorological concept, weather that occurs regularly, and that's easier to relate to.”

A reduction in mild weather days can have a tremendous economic impact because they are essential to a variety of industries that involve outdoor activities. Those include fishing and boating, as well as baseball and football, hiking and camping, and even outdoor weddings. They also include the construction industry, agriculture and transportation.

In some areas of the United States, there will actually be an increase in the number of nice weather days in the fall and spring, even as summers see more extreme heat, said Sarah Kapnick, a researcher at NOAA's Geophysical Fluid Dynamics Laboratory and a co-author. The study confirms for the first time that such observations are not just coincidence, but rather are connected to the planet's transformation under climate change.

Some parts of the globe will see a dramatic reduction in such days, she said. Others will see an increase, which can be just as harmful. In the California mountains, for example, more mild weather days have reduced snowpack and have contributed to the region's drought.

“Californians know that nice, warm, sunny weather with little precipitation isn't always a good thing because that means there is a lack of rainfall and it can affect your water resources,” she said. “So increase of mild weather days are not necessarily a positive thing because it can have change on influences of water sources and other things we haven't considered.”

Areas of the globe that are generally cooler, rainier and less humid will see an increase in mild weather days. They include northern Canada, large swaths of Europe and southern Australia. Places that are already hot and humid will have fewer mild weather days, including Brazil, a large part of Africa and the American Southeast.

The loss of mild weather will be particularly extreme in parts of Africa, South America and Asia, which could see up to 50 fewer days of mild weather. That could have large economic and public health consequences, researchers found.

Reprinted from Climatewire with permission from E&E News. E&E provides daily coverage of essential energy and environmental news at