Summer or winter: Which season is warming faster in your town?

Amid the summer’s steady stream of news about intensifying heat waves, wildfires and hurricanes, it might seem like global warming is primarily a warm-weather phenomenon. But if you pointed to a spot on the globe at random, chances are you would pick a place where winter has warmed faster than summer.

Over the past 80 years, winter temperatures have risen by about 0.28 degrees Fahrenheit per decade, outpacing the summer rate of 0.22 degrees per decade, according to an analysis of monthly temperature data. The basic reason, as Deke Arndt, director of the National Centers for Environmental Information, puts it: Cold things warm faster than warm things.

Still, in many regions, summer is warming faster than winter. In rare instances, neither season has warmed. These seasonal trends offer insights into how, decade after decade, global warming is unfolding across the world.

Summer ☀️

Winter ❄️

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Temperature change per decade, 1944-2023Temperature change per decade,
1944-2023

I’m writing this in Washington, where winter has warmed at a rate of 0.65 degrees per decade, faster than the summer warming rate of 0.4 degrees per decade.

Over time, these small increases add up. If D.C.’s warming trends continue, by the time my daughter is the same age my parents are now — in 2093 — she can expect a typical winter day to be about 4.5 degrees warmer than today. Summer days would be 2.8 degrees warmer on average.

Below, you can search cities and towns around the world to find out whether summer or winter has warmed faster.

How have the seasons

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In Washington, D.C.,

winter has warmed 1.6 times as fast as summer.

Hover on the chart to explore the data

Regardless of which season is warming faster, one thing remains clear — both winter and summer are hotter today than they used to be. On 92 percent of Earth’s surface, both seasons have warmed.

Scientists, always drawn to outliers and anomalies, are particularly interested in regions that have cooled or failed to warm as rapidly as everywhere else. One of these “warming holes” is located in the heart of North America, spanning the Great Plains of the United States and southern Canada.

Summer ☀️

Winter ❄️

Click to switch maps

Temperature change per decade, 1944-2023Temperature change per decade,
1944-2023

One widely discussed explanation for the winter warming hole involves the polar vortex, a stratospheric cyclone that circulates around the North Pole. As the Arctic has warmed, the polar vortex has grown wobblier, increasing the chances that frigid northern air spills south into the United States, counteracting the broader warming trend.

But the polar vortex cannot explain the summer warming hole. To account for this, scientists are investigating a surprising culprit: irrigation.

The vast quantity of water used to sustain agriculture in the region has led to more evaporation, which absorbs a significant amount of atmospheric energy, leaving less available to raise temperatures. Plus, all those extra water particles help form clouds and haze, which block and scatter sunlight, and further slow the warming process.

Sunlight scattering has also helped slow warming over northern India, where air pollution, rather than irrigation, is the main factor in forming clouds and haze. In winter, colder, heavier air gets trapped below the Himalayas, so pollutants cannot disperse far from their source. That makes them especially effective at blocking sunlight.

All of the largest cities where summer has warmed but winter has cooled are located on the Indian subcontinent, south of the Himalayas. These include New Delhi, Ahmedabad and Lucknow in India; Lahore in Pakistan; and Dhaka in Bangladesh — places where residents would probably have preferred their summers, rather than their winters, to have gotten cooler.

But the largest gap between winter and summer temperature trends can be found where almost no one lives. Above the Arctic Circle, winter temperatures have risen at a rate of more than 1 degree per decade over the past 80 years — nearly four times faster than summer.

Summer ☀️

Winter ❄️

Click to switch maps

Temperature change per decade, 1944-2023Temperature change per decade,
1944-2023

The Arctic’s summer air temperature has remained relatively stable because the extra energy in the atmosphere is absorbed by the Arctic Ocean, which is colder than the air during the summer months. This is similar to how a cold drink gradually warms when left in the sun.

By winter, the ocean is warmer than the surrounding air, and the flow of energy reverses: Heat radiates from the water into the atmosphere through gaps in the sea ice. As Arctic winters have warmed, sea ice has thinned, making it more susceptible to melting during the summer as temperatures rise above freezing.

Meanwhile, the coasts of Greenland bordering the Arctic Ocean are warming even in summer, a trend that scientists warn could accelerate as reflective ice continues to retreat. Even if greenhouse gas emissions were to stop, the Greenland ice sheet is projected to melt enough to raise sea levels by at least a foot by the end of the century, according to recent peer-reviewed research.