Why it is so chilly in September

Motorists on the Eldoret-Kapsabet road in Uasin Gishu County. 

Photo credit: Jared Nyataya | Nation Media Group

What you need to know:

  • Meteorologists say the warming in the eastern Atlantic Ocean (West Africa) is to blame. Due to increased pressure along the strip, some rains have been pushed as far as the western side of Kenya.
  • Although it was warm towards the end of August, the cold season had not yet come to an end, experts say noting that it will in the next few days. 

The unusual chill and rain will end in a few days, says the Met department, while explaining why it is cold this time of year.

The cold season usually occurs between June and August, but it has extended to September, Public Weather Services  assistant director Richard Muita told the Nation.

“This is happening because of climate variability and not because of climate change,” he explained. Dr Muita said the systems that cause the cold weather between June and August were still in play. Cold air from the Indian Ocean (south eastern part of Africa) has been blowing towards East Africa, causing the chill in Kenya and adjacent countries.

“The pressure at the south west part of the Indian Ocean has been high and has been pumping cold air into East Africa and elsewhere. It has persisted from June to date,” said Dr Muita, explaining that the phenomenon is “quite rare”.

Although it was warm towards the end of August, the cold season had not yet come to an end, he said, noting that it will in the next few days. In the past several days, there have been drizzles and fog in some areas.

“The lack of sunshine is making the situation worse, if you add water to a cold surface, it will become colder,” said Dr Muita.

Compared to other regions, Nairobi and the Central region have been affected the most. Wednesday, Nairobi experienced lows of 11 degrees , but was warmer than Tuesday.

On why it is raining in September, the meteorologist said the warming in the eastern Atlantic Ocean (West Africa) is to blame. Due to increased pressure along the strip, some rains have been pushed as far as the western side of Kenya, he said.

The same systems have caused some areas, including Narok, to experience ice falls. The scientist explained that the warm air, the same that is causing rains in western region, caused the ice after it passed over the cold surface air from the west Indian Ocean southerly winds.

But there is hope, as he said the cold weather is temporary and temperatures should go up from today.