Temperature Controls in the city of Harare in Zimbabwe

When most people are asked to envision the climate in Africa, they think of unbearably hot and muggy weather year around. This is not the case in the capital city of Harare, located in Zimbabwe. Though Harare's location lies in a humid subtropical climate zone, Harare also sits at an elevation of 1480 meters. Harare's climate is greatly attributed to its altitude, which moderates its climate and provides cooler, drier weather than the areas surrounding it.

Harare is the capital of Zimbabwe, and it lies at 17.86 degrees south latitude and 31.02 degrees east longitude. Because Harare lies in the southern hemisphere, it's winter months are the opposite of North America, occurring from June through August. The coldest month in Harare is July with an average monthly temperature of 56 degrees fahrenheit. Summer months in Harare are November through January, and are also the hottest months in Harare with an average monthly temperature of 70 degrees fahrenheit. According to this data, Harare has an annual temperature range of 14 degrees fahrenheit, which indicates that Harare has very little temperature change through seasons. Harare's latitude puts it in the tropics, between the equator and the tropic of capricorn. This accounts for Harare's mild seasonality, but it's moderately cool temperature is attributed to it's high elevation.
(http://www.harare.climatemps.com/)

Zimbabwe's geographic location puts Harare at an elevation of 1480 meters, almost a mile high. Altitude is one of the temperature controls we discussed in class, and is the main contributor to Harare's slightly uncharacteristic climate for the area. We learned that air temperature is controlled by solar radiation from the sun bumping into air particles, transferring heat energy from one particle to another. In higher elevations, less pressure is exerted on the atmosphere because it is further from earth's gravitational pull, therefore air is less dense at higher altitudes. Less air particles means the particles are further apart, and less collisions with solar radiation and other air particles. This means that less heat energy is transferred from the sun to the atmosphere, which in turn causes the temperature to be lower than it normally would at sea level.

A temperature control that wouldn't apply to Harare would be ocean currents. Zimbabwe is a landlocked country and therefore is not affected by any major ocean currents. There is an apparent south-easterly airflow cooling the city, but the winds affect the ocean currents, not vice versa. Ocean currents usually moderates climate, but in the tropics, climate is generally moderate already, so the effect is to a lesser extent.

According to current climate data, I would predict Harare's average annual temperature to rise in the future. I have come to this conclusion based on a few assumptions. First, I assumed that over time erosion takes place. Second, although not an accurate assumption, I assumed that erosion won't drastically affect ocean currents. Third, I assumed this climate change would take place before plate tectonics make a difference. Erosion would reduce the elevation of Harare, which would cause a rise in temperature. Also, erosion over time may bring the coastline closer to Zimbabwe, exposing Harare to the Agulhas current, which is a warm water current moving down the eastern coast of Africa. This would also cause the temperature to rise.

After looking into the climate of Harare in Zimbabwe, it is easy to see how temperature controls we discussed in class can directly affect climate of a region. Altitude is the main temperature control affecting climate in Harare, providing cooler annual temperatures than surrounding areas. Conversely, a temperature control such as ocean currents do not affect landlocked countries like Zimbabwe.