Botswana is a huge country, roughly the size of France, and extends through nine degrees of latitude. This suggests considerable variation in climate. It is landlocked and very nearly in the centre of the southern African subcontinent, on an elevated plateau of approximately 1000 metres. These factors tend to cause low annual rainfall.

The seasons in Botswana are indistinct. Rains generally start in October or November and persist through to March or April. Within that period there may be long dry spells. 

In April, temperatures begin to fall and May is generally regarded as the first month of the dry, cool winter, characterised by clear sunny days and cold nights. Spring begins in August and temperatures rise rapidly during the hot, dry period of September, October and November until the rains again breaks.

Although the rainy season is generally from October to April, there is great variation in the time of its arrival and departure, in the quantity of rain that falls and in its distribution. Rainfall decreases from the north-east of the country to the south-west, and as it does so its variability increases. Thus the north-east might expect 600 mm of rain with a variability of about 30%, whilst the drier south-west will receive, on average, only 200mm, with a variability of about 80%. Rain tends to fall in short, sometimes violent thundershowers but it is worth noting that, at any time of year, it does not normally rain on more than two consecutive days.