Climate Change Chart of Bloemfontein, South Africa

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.42 °C in the more recent period; this is an unweighted mean of monthly means, not a day-weighted annual average or a measure of daytime maximum temperatures. The largest monthly increase was in January, with a difference of +2.30 °C compared with the earlier reference period; this identifies the strongest monthly increase, not a uniform change across every month.

Changes in rainfall

Mean daily rainfall, rather than monthly rainfall totals, had an averaged-across-calendar-months difference of -0.57 mm/day in the more recent period. This unweighted mean summarizes the monthly means and does not imply that rainfall decreased in every month. The largest monthly decrease was in January, at a difference of -1.56 mm/day; this marks the strongest decrease among the reported monthly changes, not a daily change for every day in that month. By contrast, July had the largest monthly increase, with a difference of +0.10 mm/day in mean daily rainfall.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of +0.06 hours/day in the more recent period. This is an unweighted summary of monthly means, not a day-weighted annual figure, and does not indicate that sunshine increased in every month. The largest monthly increase occurred in May, with a difference of +0.36 hours/day in mean daily sunshine duration. In December, the largest monthly decrease was a difference of -0.34 hours/day; the contrasting monthly changes show why the mean should not be read as a description of each month.

Changes in snowfall

Averaged across calendar months, mean daily snowfall had a difference of 0.00 mm/day at the displayed precision. This is an unweighted mean of monthly means, and the unchanged rounded value does not establish that snowfall was absent or that values were identical beyond that precision. The largest monthly increase was shared by August / September, with a difference of +0.01 mm/day in mean daily snowfall; this monthly change can coexist with an unchanged rounded mean across calendar months.