Climate Change Chart of Stellenbosch, South Africa

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperatures show a difference of +0.67 °C compared with the earlier reference period; this is an unweighted mean of the monthly means, not a day-weighted annual average or a measure of daytime highs. The monthly pattern was not uniform: December had the largest increase, a difference of +1.71 °C, while August had the largest decrease, a difference of -0.25 °C. These extrema describe the reported monthly means, not every day within those months.

Changes in rainfall

Mean daily rainfall, averaged across calendar months, had a difference of +0.47 mm/day compared with the earlier period. This is an unweighted average of monthly means, not an annual total or a day-weighted average, so it describes the overall monthly-mean comparison rather than the rainfall on every day. The clearest monthly increase was in June, with a difference of +1.75 mm/day; by contrast, October recorded the largest decrease, a difference of -0.12 mm/day. These monthly differences show that the broader mean increase did not apply uniformly across the calendar.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, had a difference of -0.25 hours/day relative to the earlier reference period. This is an unweighted mean across monthly averages, not a day-weighted annual figure. The largest decrease occurred in August, at a difference of -0.46 hours/day; the largest increase was much smaller in May, with a difference of +0.01 hours/day. These comparisons concern average daily sunshine hours and monthly means, not the amount of sunshine on individual days.