Climate Change Chart of Cape Town, South Africa

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperatures show a difference of +0.56 °C compared with the earlier reference period; this is an unweighted mean of monthly means, not a day-weighted annual average or a measure of daytime highs. The month-specific changes were not uniform: October had the largest monthly increase, at a difference of +1.03 °C, while March had the largest monthly decrease, at a difference of -0.31 °C. These are changes in monthly mean conditions, not descriptions of every day in those months.

Changes in rainfall

Mean daily rainfall averaged across calendar months had a difference of +0.60 mm/day compared with the earlier reference period. This unweighted average describes the monthly mean daily amounts, not an annual total or monthly rainfall totals. The largest monthly increase occurred in June, with a difference of +1.98 mm/day in mean daily rainfall; that month-specific result should not be taken to represent every day or every month.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, had a difference of -0.20 hours/day compared with the earlier reference period. This is an unweighted average of monthly means, rather than a day-weighted annual measure. Monthly differences varied: March recorded the largest decrease, a difference of -0.48 hours/day, while May had the largest increase, a difference of +0.11 hours/day. These monthly mean changes do not describe sunshine on every individual day.