Namibia has a vast land surface of 824 292 km² and is characterised by a semi to hyper-arid environment with periodic droughts and erratic rainfall patterns. According to climate change predictions, the frequency and intensity of drought events will increase, and will be further aggravated by higher land surface temperatures. The objectives of this research were to quantify temporal and spatial variability and trends in the precipitation regime and the vegetation phenology of Namibia's forests and woodlands, and consequently, to correlate the long-term phenology trends and variability of Namibia's forests and woodlands to long-term precipitation and other potential determinants. As the exact spatial extent of forest and woodland areas in Namibia is not known, two layers of the Bush Information System, the 2018 canopy cover to the 2015 canopy cover, were used to derive a forest and woodland layer in accordance with the FAO definitions of forest and wooded land. The analysis of 39 years (1981 to 2020) of daily CHC CHIRPS 2.0 precipitation data verified that Namibia's yearly precipitation is temporally and spatially highly variable and erratic, and no significant trends could be identified in the long-term annual precipitation to suggest any trends towards a drier or a wetter climate. It moreover confirmed climate change projections, which predict that Namibia's seasonal precipitation will be characterised by more extreme hydrological events. The SPI (Standardised Precipitation Index) analysis of 39 years of precipitation records showed, that both the wettest and the driest years in these 39 years occurred in the past ten years. The analysis of the precipitation data suggests that most often, for the greater part of Namibia's summer rainfall area, the rainfall season starts during the month of January, while the rainfall season generally ends either in February or in March. The results of the regression analysis of 26 years (1981 to 2006) of daily AVHRR NDVI data suggested an increasing trend in average annual NDVI for all forest and woodland areas, for that period, and a significant increasing trend for the Angolan Mopane woodlands, the Kalahari Acacia-Baikiaea woodlands and the Kalahari xeric savanna ecoregions. The analysis of the start and end of the growing season suggests that the growth season is spatially and temporally highly variable; and for most parts of the Namibian land surface, the growing season starts between September and December, while it appears to be most common that the growth year ends between September and November of the following year. The analyses of the start and end of the rainfall and growth seasons, suggest an earlier start of the rainfall season, and an earlier start and end of the growth season for the north-eastern part of Namibia, while, for the western and north-western part of Namibia, it suggests a later start and end of the rainfall season and a slightly earlier start and end of the growth seasons. The spatial distribution of the average rainfall season start and the average growth season start, by Terrestrial Ecoregion in the woodland areas, suggests that the growth season in Namibia starts in the Nama Karoo, in the south of Namibia, in the first week of November, while the rainfall season starts in the Nama Karoo, in the last week of November. The growth season ends for most of northern, central, north-eastern and eastern Namibia, in the last week of October, while the rainfall season ends in mid-March in the Nama Karoo. While no correlation could be identified between the start of the rainfall season and the start of the growing season, nor for the end of the rainfall season with the end of the growing season, the average total precipitation and average maximum NDVI appear to be following a similar moving average trend. With this research, the potential of using available earth observation products, in particular the products used for this research, the CHC CHIRPS 2.0 satellite-based precipitation data and the NOAA AVHRR NDVI data, to quantify temporal and spatial variability and trends of precipitation regimes and vegetation phenology, was explored successfully and demonstrated that the scope for using these data resources is very promising in obtaining larger regional, national and even trans-boundary insight into our climate and vegetation phenology. Keywords: Namibia, climate change, precipitation, vegetation phenology, woodland, forest.