Some days, it’s easy to tell who checks the weather before getting dressed for the day and who does not. In the District, Jan. 26 was one such day.
As temperatures soared up to a record-breaking 80 degrees and record-high humidity to match, some people could be spotted wearing—or carrying—heavy winter jackets while others had donned shorts and tank tops.
“I wore sweats and a hoodie, and it definitely was not the right thing to wear,” said Badi Cross, a senior at Howard University. “I went outside and I was like, it’s hot as hell out here.”
The confusion of sartorial choices on Friday reflected a rollercoaster week of weather in the District: just a week prior, a major snowstorm hit the city, accompanied by days of below-freezing temperatures.
Cross, who came to the District from Portland, Oregon, said he rarely checks the weather and was caught off guard. “I was sweating by the time I got to campus,” he said of his five-minute walk from home.
Even indoors, things were different. Joy Lawson, director of the Young Women’s Entrepreneurship Program at Elizabeth Seton High School, told the Informer she had to turn on the air conditioning unit in her classroom.
“It was an odd day in January,” Lawson, 30, said.
Another Shattered Heat Record
Since the start of documentation in 1872, D.C. has never before reached 80 degrees earlier than mid-February, and even that has only happened four times in over 150 years. Most years, the first 80-degree day hits in March or April.
The previous mark for the hottest day in January was 79 degrees, which happened on the same date in 1950. The Washington Post’s Martin Weil looked into his paper’s archives last week to find the front-page, above-the-fold story about the event. The original author apparently recommended children take note of the date, writing “you’ll boast of it when you’re old.”
More recently, unseasonable temperature spikes during winter have become more common in the region. In the 50 years between 1873 and 1923, the District hit 70 degrees 17 times during December, January or February. Between 1973 and 2023, DC crossed that threshold 44 times during winter months.
That’s because gasses from burning fossil fuels are trapping heat inside our atmosphere, making the whole planet hotter. On average, D.C.’s winters have gotten 3.6 degrees warmer since 1970, according to data from Climate Central. Climate change causes baseline temperatures to rise, and it also makes temperature spikes like the one on Jan. 26 more likely to occur.
“It feels like I’m not going to have a very good planet to raise my kids on,” Cross, the Howard senior, said. “I was kind of happy it was warm—I definitely am not a fan of the cold. But I was also like ‘it’s definitely not supposed to be like this today.’”
Warm, Humid Air + Cold Air = Fog
Another record-breaking weather event occurred last week when dense fog blanketed a huge swath of the U.S., causing more “dense fog advisories” to be issued nationwide than on any other day since documentation started in 2005. The fog broke that record on Tuesday, Wednesday and Thursday mornings this week, with each day having more advisories than the last.
The DMV saw heavy fog roll in Thursday night and stay through Friday morning, with commuting drivers facing very low visibility. Washingtonians who didn’t have to get behind the wheel posted dozens of beautiful, sometimes eerie, photos of D.C.’s monuments, bridges and other iconic places shrouded in mist.
It’s no coincidence that the fog moved in just before the District got weirdly warm. When humid warm air flows over colder air near the ground (which was still chilly from the snow and ice) it creates the perfect conditions for what’s called “advection fog.”
“When you have a cold front and a warm front meeting, you have that cold, denser air that’s flushing underneath the warmer air,” said Dr. Osinachi Ajoku, a researcher and assistant professor of atmospheric science at Howard University. “Usually, when those two air masses meet, you have a lot of moisture and convection that happens.”
Another factor that affects fog formation is pollution, because the tiny water droplets that create the ground-level clouds can only form when sticking to particles in the air, Ajoku said. That means that in a far-reaching fog event like last week’s, areas near pollution sources like busy freeways or power plants tend to experience denser fog than places with cleaner air. Those pollution sources are disproportionately located near Black and low-income communities, as a result of redlining and other racist policies.
It’s not clear yet how climate change and milder winters might impact these fog events.
Researchers are still learning whether a warmer world will cause more clouds to form close to the ground or fewer, or whether those clouds will be more or less likely to become thick enough to make it hard for us to see.
“One of the toughest things to predict in our field is actually the formation of clouds,” Ajoku said. “I think this will be a future topic of research going forward, specifically in the wintertime.”
