The Kenya Meteorological Department says the onset of the cold weather season of June, July, to August has began, a situation mostly resulting from prolonged hours of overcast skies due to cloudy conditions that lead to cold and chilly conditions.
The cold weather conditions arise from a combination of factors, the movement of the sun, is one such factor as it results in different seasons over the 12 months, much as it is the earth that revolves around the Sun on its axis northwards and southwards.
In June, the sun is on the Tropic of Cancer, with the solstice happening on June 21st, and two weeks after the Solstice, the Earth will reach its farthest point from the Sun on July 4, 2022.
This is known as the Aphelion. The opposite happens in the Perihelion this is when the Earth in it’s orbit is nearest to the Sun. In 2022, Earth was at perihelion on January 4th this is again two weeks after the Solstice on the Tropic of Capricorn on December 22nd.
The story that was doing rounds about the aphelion could result into a cold weather season is not entirely true, this is because during the Aphelion, countries in the northern hemisphere are actually experiencing summer, which is a warm season.
The cold weather being experienced in the country during the June, July to August season is due to the overcast skies, that do not allow the sun’s rays through, when this happens then the weather is cold.
“During the June, July, to August period, most areas in the Highlands East of the Rift Valley, including Nairobi County, usually experience cool and cloudy conditions with occasional drizzle or light rains,” says Dr. Gikungu in the statement.
Adding that: “Prolonged hours of overcast skies, cloudy conditions cause cold and chilly conditions on some days.”
The other factor is that, when the sun is in the northern hemisphere, there is low pressure in the northern hemisphere, at this time, it is the opposite in the southern hemisphere where at this time it is cold with high pressure.
Since the weather is a system, the wind then start blowing from the southern hemisphere northwards, transporting the cold air northwards.
This situation combined with reduced penetration of the Sun’s rays results in the cold weather.
During the cold season, there is a possibility of an increase in respiratory diseases like asthma, pneumonia, flu and the common cold are likely to increase over Nairobi County, the Highlands East of the Rift Valley, parts of Central Rift Valley, and Highlands West of the Rift Valley due to the expected cold conditions.
This year parts of Northwestern region is also expected to experience below average temperatures.
“The general public is advised to adopt warm dress codes and follow advice from the Ministry of Health,” says Dr. Gikungu in the statement.
“The public is also advised to avoid using charcoal jikos in poorly ventilated houses as jikos produce carbon monoxide gas that is lethal when inhaled.” He added.
Cases of Malaria are also expected, “but this may not rise beyond normal transmission due to the predicted reduced temperatures during the season.” The season could also see food shortage being experienced in the Arid and Semi Arid Lands (ASAL) areas of the northern and eastern sectors of the country which could lead to an increase in malnutrition-related diseases.
“The food security assessment should therefore be carried out to identify the most vulnerable communities and provide them with water, food or food supplements” says Dr.
The cold season is also characterised by formation of fog, fog is a low lying cloud formed when water vapor, condenses quickly, during condensation, molecules of water vapor combine to make tiny liquid water droplets that hang in the air forming the fog.
You can see fog because of these tiny water droplets. Water vapor, a gas, is invisible. Fog formation in the areas that are expected to experience cold and cloudy conditions may pose a danger to motorists due to low visibility.
The Weatherman is advising motorists to be cautious when driving along the Nairobi to Naivasha Highway and particularly on the Kikuyu-Kinungi stretch where visibility is often reduced to a few meters.
Foggy weather is also likely to occasionally cause disruptions to operations at the Wilson Airport and Jomo Kenyatta International Airport (JKIA).
Light rains and drizzles may result in slippery road and motorists are advised to take “utmost care in order to minimize accidents that may happen as a result of the wet weather conditions.” from such weather conditions.