Responsiveness of Dichrostachys cinerea to seasonal variations in temperature and rainfall in central Namibia

•Growth rings displayed fluctuating but strengthening effects of temperatures.•End of rainy season and beginning of winter are conducive periods for growth rings.•Development of growth rings showed a somewhat lagged response to rainfall.•Results correlated with late summer warming, lasting up to half of the rainy season.•Effects of temperature on growth ring are more severe at Kuzikus than at Waterberg.