Another hot day in Gauteng: 10 Things you should know about heat waves
If you have that condition for three days persistently, that's when you have a heat wave
THE South African Weather Service has again warned about heat wave conditions in Gauteng and North West on Tuesday.
Expected temperatures in Johannesburg today could reach 34°C.
Heat wave conditions started on Saturday and should end by Wednesday.
Temperatures in Johannesburg topped 32°C on Monday, while temperatures in the North West are expected to soar as high as 36°C by Wednesday.
According to the weather service they take the average of the hottest month and add five degrees to it. If you have that condition for three days persistently, that’s when you have a heat wave.
10 Things you should know about heat waves
1. A heat wave is a prolonged period of excessively hot weather, which may be accompanied by high humidity, especially in oceanic climate countries.
2. Heat waves form when high pressure aloft strengthens and remains over a region for several days up to several weeks.
3. Temperatures that people from a hotter climate consider normal can be termed a heat wave in a cooler area if they are outside the normal climate pattern for that area.
4. Severe heat waves have caused catastrophic crop failures, thousands of deaths from hyperthermia, and widespread power outages due to increased use of air conditioning.
5. During heat waves, the human body is pushed beyond its limits. Under normal conditions, the body’s internal thermostat produces perspiration
that evaporates and cools the body. However, in excessive heat and high humidity, evaporation is slowed and the body must work extra hard to
maintain a normal temperature.
6. Abnormally hot temperatures cause electricity demand to increase when air conditioners are straining to overcome the heat.
7. If a hot spell extends to three days or more, night time temperatures do not cool down and the thermal mass in homes and buildings retains the heat from previous days.
8. The Australian summer of 2012-2013, known as the Angry Summer or Extreme Summer, resulted in 123 weather records being broken over a 90-day period, including the hottest day ever recorded for Australia as a whole, the hottest January on record, the hottest summer average on record, and a record seven days in row when the whole continent averaged above 39°C.
9. On January 26, 1936, a heat wave hit South Africa and temperatures soared in places to up to 44,4°C.
10. Heat waves kill more Americans than other natural disasters such as floods, lightning, tornadoes and hurricanes.
