Kenya is the world's leading exporter of black tea and the commodity is a major foreign exchange earner for East Africa's biggest economy.
Output of tea in the first nine months of 2015 fell to 271.4 million kilograms (kg) from 315.7 million kg in the same period last year, data from the Agriculture, Fisheries and Food Authority's website showed.
Kenya's tea exports also dropped to 328 million kg in the period to September, from 376.8 million kg during the same period last year. The differences in export and production figures usually arise from unsold tea held over from the previous year.
Kenya experienced drought conditions early this year which affected the output of tea while processing factories received fewer deliveries.
Tea production in the east Africa nation is expected to improve over the final quarter of the year due to more rain in most key growing areas.