Gaborone has a hot semi-arid climate . Most of the year, Gaborone is very sunny. The summers are usually hot. The nights are cool. Usually, the summers with little rainfall are warmer than summers with regular rainfall. If there is a drought, the hottest temperatures of the year are usually in January or February. If there is normal rainfall, the hottest temperatures are usually in October, right before the rain starts. During the winter, days are still warm, and the nights are cold.
There are on average seventy-four days per year with temperatures above 32 °C (90 °F). There are on average 196 days per year with temperatures above 26 °C (79 °F). There are on average fifty-one days per year with temperatures below 7 °C (45 °F). There is on average one day per year with temperatures below 0 °C (32 °F). The average dew point peaks around January and February at 16 °C (61 °F) and hits the lowest levels in July at 2 °C (36 °F). The average dew point in a given year is 10 °C (50 °F).
Precipitation in Gaborone is scanty and erratic. Most of the rainfall in Gaborone falls during the summer months, between October and April. There are on average forty days of thunderstorms per year, most of them happening during the summer months, and four days of fog, usually happening during the winter months. Gaborone has been affected by three floods based on records going back to 1995, one in 2000, one in 2001 that caused an estimated 5,000,000 Botswana pula worth of damage, and one in 2006.
The highest humidity occurs in June at 90% while the lowest humidity is in September at 28%.
Solar irradiance ranges from 4.1 kWh m d in June to 7.3 kWh m d in December.
It is windier from September to November at 14 km/h (8.7 mph), and it is calmer from May to August at 8 km/h (5.0 mph). The average wind speed in a given year is 12 km/h (7.5 mph).