A heat wave, or heatwave,is a period of excessively hot weather, which may be accompanied by high humidity, especially in oceanic climate countries. While definitions vary, a heat wave is usually measured relative to the usual weather in the area and relative to normal temperatures for the season. Temperatures that people from a hotter climate consider normal can be called a heat wave in a cooler area if they are outside the normal climate pattern for that area.
The term is applied both to hot weather variations and to extraordinary spells of hot which may occur only once a century. Severe heat waves have caused catastrophic crop failures, thousands of deaths from hypothermia, and widespread power outages due to increased use of air conditioning. A heat wave is considered extreme weather that can be a natural disaster, and a danger because heat and sunlight may overheat the human body. Heat waves can usually be detected using forecasting instruments so that a warning call can be issued.
What Causes a Heat Wave?
A heatwave occurs when a system of high atmospheric pressure moves into an area and lasts two or more days. In such a high-pressure system, air from upper levels of our atmosphere is pulled toward the ground, where it becomes compressed and increases in temperature.
This high concentration of pressure makes it difficult for other weather systems to move into the area, which is why a heatwave can last for several days or weeks. The longer the system stays in an area, the hotter the area becomes. The high-pressure inhibits winds, making them faint-to-nonexistent. Because the high-pressure system also prevents clouds from entering the region, sunlight can become punishing, heating up the system even more. The combination of all of these factors come together to create the exceptionally hot temperatures we call a heatwave.
Heat Waves Can Be Deadly
While the phrase “dangerous weather” may conjure up images of blizzards, hurricanes or tornadoes, it’s important to remember that heatwaves can be deadly. During a heatwave, you can protect yourself by staying out of the sun during the hottest parts of the day, avoiding strenuous activities, and keeping yourself hydrated with plenty of fresh water.
And when humidity and dew points are high along with the temperatures, things can get very uncomfortable!
Greenhouse gases are trapping more heat in the Earth’s atmosphere, which is causing average temperatures to rise all over the world.
What’s happening now?
Temperatures have risen during the last 30 years, and 2001 to 2010 was the warmest decade ever recorded. As the Earth warms up, heat waves are becoming more common in some places, including the United States. Heat waves happen when a region experiences very high temperatures for several days and nights.
The choices we make now and in the
What will happen in the future?
next few decades will determine how much the planet’s temperature will rise. While we are not exactly sure how fast or how much the Earth’s average temperature will rise, we know that:
- If people keep adding greenhouse gases into the atmosphere at the current rate, the average temperature around the world could increase by about 4 to 12°F by the year 2100.
- If we make big changes, like using more renewable resources instead of fossil fuels, the increase will be less—about 2 to 5°F.
Extremely hot weather takes a large toll on the human body. In an average year, the summer heat in the U.S causes about 175 deaths. People most at risk for heatstroke are the elderly, small children, and people with weight and alcohol problems. Always listen to the radio and television for the latest information and instructions for your area.
HEAT WAVE SAFETY TIPS:
- Slow down. On a hot day, don’t perform strenuous activities.
- Dress for summer. Wear lightweight, light-colored clothing.
- Drink plenty of water. Your body needs water to keep cool.
- Spend more time in air-conditioned places.
- If you don’t have air-conditioning, then have plenty of fans.
- Don’t get too much sun.
- Heatstroke, heat exhaustion and sunstroke are possible with prolonged exposure to the heat.
- If someone gets heatstroke or heat exhaustion seek medial attention immediately