Botswana's climate is semi-arid. Though it is hot and dry for much of the year, there is a rainy season, which runs through the summer months. However, rainfall tends to be erratic, unpredictable and highly regional.
‘Pula’, one of the most frequently heard words in Botswana, is not only the name of Botswana's currency, but also the Setswana word for rain. So much of what takes place in Botswana relies on this essential, frequently scarce commodity.
Fall – March to April
Winter – May to August
Spring – September to October
Summer - November to March
During the winter, the days are dry, sunny, clear and cool to seductively warm while evening temperatures drop sharply. Day time temperatures generally reach 25º C (77 F) and evening temperatures can be as low as 2ºC (36 F) and in some areas can plummet below freezing. Virtually no rainfall occurs during the winter months.
The summer season begins in November and ends in March. In October the weeks preceding the coming of the rains tend to be the hottest with temperatures soaring up to 40ºC (104 F) or more. Cloud coverage and the arrival of the first rains towards the end of November or in early December cool things down considerably, although usually only for a short period. During the rainy period, which lasts until the end of February or early March, the days are hot and generally sunny in the morning with afternoon thunderstorms – usually in short, torrential downpours during the late afternoon. Day time temperatures can rise to 38ºC (100 F) and night time temperatures drop to around 20ºC - 25ºC (68 F – 77 F).
The winter season begins in May and ends in August. This is also the dry season when virtually no rainfall occurs. Winter days are invariably sunny and cool to warm; however, evening and night temperatures can drop below freezing point in some areas, especially in the southwest.
The in-between periods - April/early May and September/October - still tend to be dry, but the days are cooler than in summer and the nights are warmer than in winter.
In summer during the morning period humidity ranges from 60 to 80% and drops to between 30 and 40% in the afternoon. In winter humidity is considerably less and can vary between 40 and 70% during the morning and fall to between 20 and 30% in the afternoon.