Across the country, more than 7,700 daily temperature records were broken last month, on the heels of the fourth warmest winter on record.
While it might be time to lie on a blanket in the park, climate scientists are worried. They say all these sunny days are actually an extreme weather event, one with local and global implications.
In Iowa, March was so hot — a record-breaking 84 degrees — that some crops there, like oats, are now running way ahead of schedule.
Joe Prusacki, a statistician with the Department of Agriculture, says this time of year Iowa usually has just 7 percent of its oats planted.
"Right now, they're at 58 percent planted," Prusacki says. "That's because if you plant the crop now, it's going to germinate and grow."
It's hard to say whether that could be good for farmers, since crops could still get hit with frost as late as May.
More Than Just Warm Weather
Even with the early warm weather, that chance of a hit of frost could spell trouble for farmers. But if you've got allergies, you may already be in trouble.
"Barring some sort of dramatic snow or change, we probably won't see much relief until midsummer when things do calm down," says Jim Sublett, an allergist in Louisville, Ky. He says patients have been coming to him with runny noses, itchy eyes and even asthma flare-ups since mid-February, about a month earlier than normal.
"The problem with that is because of the longer exposure, those people may be at risk of having more severe problems as the season goes along," he says.
Vermonters are dreading early leaves for an entirely different reason. Arnold Coombs, a seventh-generation maple syrup farmer, says that when he was a kid, a tree would never be tapped before the first Tuesday in March.
"This year, you had to be tapping by the second week just to get those first runs of sap," he says.
Every spring, syrup farmers have to move fast because when trees sprout leaves, the chemical composition of the syrup changes. As soon as that change happens, Coombs says, the syrup is not very good. The problem with this year is that happened very early.
So production is down and you might see syrup prices up this year. You might also see higher crime, says Martin Flask, director of public safety in Cleveland.
Flask says people are out, it's light later in the day and there are more children playing. Even though, in the long term, crime is trending downward in Cleveland, homicides and burglaries are up compared to this time last year.
"We've seen a significant spike that, in our mind, can be caused by nothing else but the weather," Flask says.
Scientists say we'll probably see more bug bites, Lyme disease and accidents, too, since people are outside more.
How Unusual Is The Early Heat?
Climatologist Heidi Cullen with the research organization Climate Central has been closely following the spring heat. She tells weekends on All Things Considered guest host Laura Sullivan that it's hard to get a sense of how big of a deal the so-called "warm wave" is because it's so nice.
"We were breaking records by upward of 40 degrees in some places," says Cullen, the author of The Weather of the Future. "It was this really ironic, extreme weather event because it was like, 'I'm loving this,' but at the same time it was incredibly unusual."
When you think of extreme weather, you often think of dramatic events like tornadoes, droughts or hurricanes. It's hard to view a warm, spring day as an extreme weather event, and Cullen says that's one of the challenges of talking about climate.
"Even heat waves, when they're happening in the midst of July or August, are hard to really visualize," she says.
Though scientists are hesitant to link tornado outbreaks, like those that struck near Dallas this week, to climate change, Cullen says it is fair to say that warmer weather creates extreme weather.
If you increase the Earth's average temperature by about 1.4 degrees, which we've done, you see it penetrate into the weather, she says, especially with heat extremes. This past March is what Cullen calls a storybook example of that.
"We expect [heat waves] to last longer, which this one did, to affect broader areas, which this one did, and to be more intense, which this one was," she says.
Cullen says the sooner work begins on the climate change issue, the better. There are time lags in the system, she says, so what we're seeing now is a result of things that happened in the 1980s.
"Because of the time lags in the system, if you wait, you've really got problems," she says. "So it's this exercise in ... trusting the science.
"The science tells us that if we don't do anything about this problem, that by the middle and the end of the century, we're looking at really a radically different climate," she says.
We Are All Vulnerable
The United Nations' International Panel on Climate Change released a report this week that says we're more likely to face extreme weather events in the coming decades. That includes things like more intense heat weaves, heavier rainfalls and longer droughts.
The report, however, doesn't focus on things to prevent or slow climate change. Instead, it tells people how to cope better with the weather disasters it says we're more likely to face.
Christopher Field, a climate scientist at Stanford University, was a top editor on the report. He tells NPR's Sullivan that statistics on disaster loss are both interesting and tragic.
"What you see historically is that the economic losses tend to be greatest in the developed countries," Field says, "but the loss of life tends to be overwhelmingly concentrated ... in the world's developing countries."
That doesn't mean that developing countries don't take smart steps to avoid weather disasters, he says. He cites Bangladesh's ability to deal with cyclones.
The small nation in South Asia has had some of the most destructive cyclones in history. Field says the nation minimized the loss of life when Cyclone Sidr hit in 2007 by using smart, relatively low-cost strategies like early-warning systems, platforms above the storm surge for people and livestock, and civilian response teams,
Though about 3,447 people died in the cyclone, there were far fewer fatalities than when a similarly powerful cyclone hit the area in 1991, killing 143,000.
Field says a lack of resources, civil strife and no recent disasters prevent some areas from implementing these strategies.
One thing that is certain is that essentially every part of the world is vulnerable to some kind of extreme weather or disaster, so being prepared is essential.
"When we look at where the extremes have occurred in the U.S. over the last year, we see them essentially everywhere: droughts in the West, floods in the Northeast [and] tornadoes in the middle," he says. "It really is the case that there is no place on the map that is immune to climate change and disasters."