You arise in the morning and peer out your window. There's a misty dew coating the grass, and you can feel a chill in the air through the glass. Looks like you'll need to add a jacket to your outfit before you head to the bus stop.
After a productive day at school, you run home from the bus, anxious to grab a snack and play with your friends. You don't need that jacket any longer, though. With the Sun shining down, the temperature is perfect for a game of hide and seek outdoors in your short sleeves.
You've probably seen this cycle play out day after day for many years. Early in the morning, it's much colder than it is late in the afternoon. But why is that? Why isn't it the same temperature all day long? Why do we have to put up with temperature swings throughout the day?
Our daily temperatures follow what meteorologists refer to as a diurnal cycle. As you've experienced many times, this means that a high temperature is reached late in the afternoon while the temperature bottoms out late at night just before dawn.
Our daily temperature swings are usually a gradual process that depends in large part on the effect of the Sun's rays upon Earth. At dawn, the Sun's rays begin to heat Earth's surface very slowly. Like a pot of cold water takes time to reach a boil, Earth's surface must absorb a good amount of sunlight before it begins to heat up.
Earth's surface can store quite a bit of heat. As it begins to warm up, it also heats up a very thin layer of air directly above the surface. That thin layer of air then begins to heat the air above it via conduction.
Even though the Sun's rays are at their most concentrated at noon, temperatures usually don't reach their peak for the day until several hours later. This is because the ground continues to store and radiate heat even as the Sun's rays begin to diminish as dusk approaches.
After the Sun goes down, temperatures eventually drop as Earth's surface loses its stored heat and can no longer heat the air. On any given day, the temperature swing from low to high temperatures will be approximately 20-30 degrees Fahrenheit.
Of course, not all days follow that pattern. Some days the high and low temperatures are only a few degrees apart. On other days, however, wild temperature swings can see temperatures drop or increase 50 degrees or more!
These differences in temperature swings can be caused by a wide variety of factors. For example, the length of the day can affect temperature swings. Shorter days mean Earth has less time to heat up. Likewise, many other factors, such as cloud cover, elevation, wind, and humidity can also play a role in temperature swings.
Over the course of history, some people have witnessed some of the wildest swings in temperature ever recorded. For example, on January 22, 1943, in Spearfish, South Dakota, residents saw temperatures rise from -4º F to 45º F in just two minutes! After peaking at 54º F, the temperature then fell 58 degrees in less than a half-hour back to -4º F again.
Can you imagine such a wild swing in temperatures? Oklahoma and Texas cities have also seen temperature swings of 66 degrees in a single day. If you think these temperature swings play havoc with your dress code, you're right. They can also have an impact on your health.
Some experts believe that rhinitis, an inflammation in the nose and sinus cavity, can be triggered by pressure and temperature changes. When temperature swings are larger than normal, those affected can experience congestion, headaches, and allergy-like symptoms.