Too hot for a picnic, warm enough for a winter walk: Where have America’s pleasant-weather days gone?

As fall arrives in United States, and the cool breeze is grazing your skin with a sense of comfort, you feel joy. You like the sunshine and the breeze. You keep hoping for a pleasant weather in the weekend as you want to have a picnic outside with your friends and family. You make all the plans, prepare the picnic baskets, some card games and finally head out on a Saturday afternoon.

It’s sunny but the weather looks really good from inside your car. You can’t wait to go out and have fun. Once you are there in the park in that sunny afternoon, suddenly the sunshine feels too punishing. You start looking for shade but that also doesn’t provide you any respite. So you back home, turn on the air conditioner and then have your lunch in peace.

The winter afternoon which was supposed to make you feel comfortable with the sunshine, suddenly started feeling like late summer. So you need to think about a question: is warming changing when Americans can comfortably enjoy the outdoors?


What counts as pleasant weather?

A pleasant day means different things to different people. A runner may prefer cooler air than someone sitting outside a cafe.

Researchers at the Massachusetts Institute of Technology explored the idea through “outdoor days”. Their 2024 study which was published in Geophysical Research Letters counted days with average temperatures between 10°C and 25°C, or 50°F and 77°F and observed it.

They also tested an alternative measure by adding the humidity factor. Such thresholds help compare climates, but cannot capture everybody’s comfort or every outdoor condition. A daily average can also conceal an uncomfortable afternoon.

Are comfortable days disappearing across America?

The answer is both yes and no and it depends on location and season.

The MIT research says that there would be fewer comfortable outdoor days during warmer months but will change as we move towards colder periods. Southern and southeastern regions could face more losses in annual outdoor days while parts of the Northwest could gain.

The findings complicate the idea that warmer weather automatically means more opportunities to spend time outside. Warming can bring a cold day into a comfortable range but it gets to warm then people would prefer to stay indoors and in the comfort of fans and air conditioning.

What could happen in Miami, Chicago and Seattle?

Research from NOAA and Princeton University offers city-level examples. Their 2017 analysis defined mild days using temperature alongside rainfall and humidity. It projected Miami’s annual total falling from a historical baseline of 97 days to 69 by 2081–2100.

Chicago’s count fell from 77 to 68. New York City declined from 83 to 77, while Seattle increased from 88 to 97.

Those figures are conditional, long-term model estimates. They are neither a forecast for next year nor directly interchangeable with MIT’s differently defined outdoor days. They show why a national average can obscure sharply different local experiences.

What do recent observations show?

A May 2026 Climate Central analysis provides a more recent picture of summer warming.

It found that summers warmed between 1970 and 2025 in 236 of 243 US cities examined. Across those warming locations, the average increase was 2.6°F.

Houston recorded an estimated increase of 58 hotter-than-normal summer days since 1970. New Orleans recorded 53.

“Hotter than normal” refers to local temperature benchmarks in the past years. Those figures do not count pleasant days lost, but they help explain why familiar summer routines may increasingly require checking the forecast.

Can a pleasant winter replace a comfortable summer?

An annual total cannot tell the whole story.

A mild Tuesday in February may offer little consolation to a family whose outdoor plans depend on summer school holidays. Seasonal shifts could also change when destinations attract visitors, mostly those places with snowfall and beautiful fog.

MIT’s researchers found a relationship between outdoor days and visiting national parks. Their work suggests that changing comfort could affect tourism, including destinations in Florida. The precise business consequences would depend on how visitors and operators adapt.

For households, the loss may feel smaller but more frequent: another outing shortened or another afternoon spent indoors.