Climate Change Chart of Gaborone, Botswana

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.03 °C compared with the earlier reference period. This is an unweighted comparison of monthly means, not a day-weighted annual average, and it describes the average difference rather than a change occurring in every month. The largest monthly increase was in January, with a difference of +1.89 °C. These are monthly mean temperatures, not daytime maximum temperatures.

Changes in rainfall

Mean daily rainfall averaged across calendar months shows a difference of -0.59 mm/day in the more recent period. This unweighted mean of monthly means is not a day-weighted annual average, and the overall difference does not imply that rainfall decreased in every month. The largest monthly decrease was in March, where the difference was -1.64 mm/day. By contrast, July recorded the largest monthly increase, with a difference of +0.05 mm/day. These figures describe mean daily rainfall, not monthly rainfall totals.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of +0.01 hours/day compared with the earlier reference period. This is an unweighted average of the calendar-month means, not a day-weighted annual figure; the small average difference does not mean that every month shifted in the same direction. The largest monthly increase occurred in November, with a difference of +0.40 hours/day, while the largest decrease was in February, at -0.38 hours/day. The monthly contrasts therefore give useful context for interpreting the near-small mean difference, without implying a continuous trend between the reference periods.