CLOSE
iStock
iStock

Why Your Car Dashboard Says It's a Lot Hotter Than It Really Is

iStock
iStock

When you first turn on your car in the middle of a sunny day, chances are your dashboard probably says it’s quite hot out. Like, a lot hotter than it feels. There’s a reason why car thermometers don’t always seem accurate, according to atmospheric scientist Greg Porter at The Washington Post.

Your dashboard temperature reading actually comes from something called a thermistor, which is similar to a thermometer but instead of mercury, it uses electrical current to measure changes in temperature. (Remember that temperature is an indication of how fast or slow gas molecules in the air are moving around. The higher the reading, the greater the molecules' kinetic energy.) In a car, that thermistor is located just behind the grill in the front of the car. Therein lies the problem: Your car's temperature readings come from an unusually hot location.

Asphalt roads get really, really hot in warm weather (enough so that cities become significantly hotter than their greener surroundings in the summer), so a temperature reading taken just above the surface of the road isn’t going to be super accurate. Heat radiates up from the road—as you can see on particularly hot days when the highway starts to look shimmery—and the thermistor in your car picks up that excess heat. It’s like measuring the temperature of a large room by sticking the thermometer an inch away from the fireplace.

That doesn’t mean your dashboard temperature readings are useless. When it’s not as hot out, there isn’t much interference from heat rising off the road. It’s also more effective when you’re moving—if you’re traveling down the highway, it will pick up less heat radiation from the road than if you were sitting in a parked car. However, Porter warns, the thermistor isn’t sensitive enough to distinguish between one-degree differences, which can be dangerous if you’re driving in the winter and need to know if temperatures have hit freezing or are floating just above.

In short, as nice as it is to know how temperatures are changing from one destination on your road trip to another, take that dashboard number with a grain of (road) salt.

[h/t The Washington Post]

nextArticle.image_alt|e
iStock
arrow
Weather Watch
It Just Snowed In the Sahara for the Second Time In Less Than a Month
iStock
iStock

The town of Aïn Séfra, Algeria might need to find a new nickname. Though it’s often referred to as “The Gateway to the Sahara,” the 137-year-old province in northwest Algeria is currently digging out from a rare—and unexpected—snowstorm that left the desert town covered in several inches of snow and battling sub-zero temperatures.

While the Daily Mail reported that “locals took to the nearby sand dunes to enjoy the unusual weather,” the strangest part of the story is that this is Aïn Séfra’s second snowfall in less than a month. On Sunday, January 7, a freak blizzard left parts of the Sahara blanketed in as much as 16 inches of snow.

This most recent storm marked the region’s fourth snowfall in nearly 40 years; in addition to January's dose of the white stuff, the area has been hit with other surprise wintry events in February 1979 and December 2016.

But North Africa isn’t the only area that’s seeing record-breaking weather events. On Saturday, February 3, 17 inches of snow fell on Moscow within 24 hours in what the country has dubbed “the snowfall of the century.” In mid-January, Oymyakon, Russia—a rural village in the Yakutia region, which is already well known as one of the coldest inhabited areas of the world—saw temperatures drop to -88.6°F, making it chilly enough to both bust thermometers and freeze people’s eyelashes. And you thought dealing with single-digit temperatures was tough!

[h/t: Daily Mail]

nextArticle.image_alt|e
Vasily Maximov, AFP/Getty Images
arrow
Weather Watch
Record-Breaking 17 Inches of Snow Covers Moscow in 24 Hours
Vasily Maximov, AFP/Getty Images
Vasily Maximov, AFP/Getty Images

Moscow sees some of the most brutal winters of any world capital, but even locals weren't prepared for the most recent winter storm to batter the city. As Newsweek reports, a record-breaking 17 inches of snow buried Moscow within 24 hours.

Roughly 7 inches of snow fell just on Saturday, February 3, and the deluge continued through the following Sunday. The accumulation has already been dubbed the "snowfall of the century," and officials expect up to 3 additional inches to cover the ground over the next three days.

The sudden blizzard has brought life to a stand-still in the metropolis of 12 million. The mayor is warning motorists to stay off the roads as around 15,000 snowplows clear the snow. About 2000 trees have been toppled by the storm, injuring at least five people and killing one.

Even as the worst of the weather winds down, over 40,000 people in Moscow and the surrounding regions are without power. Meanwhile, traveling in and out of the city has become close to impossible: Around 100 flights are grounded at the local airport indefinitely and at least 10 have been canceled all together.

The historic snowfall hasn't stopped many of Moscow's tougher residents from venturing outside. Check out photos from the event below.

Person cross-country skiing over snow in Moscow.
Yuri Kadobnov, AFP/Getty Images

Walking through a blizzard in Moscow.
Yuri Kadobnov, AFP/Getty Images

Walking through the snow in Moscow.
Yuri Kadobnov, AFP/Getty Images

Walking through the snow in Moscow.
Yuri Kadobnov, AFP/Getty Images

[h/t Newsweek]

SECTIONS

arrow
LIVE SMARTER
More from mental floss studios