Climate Change Chart of Freetown, Sierra Leone

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +0.75 °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 maximum temperatures. The largest monthly increase was in December, with a difference of +1.13 °C. This identifies the strongest increase among the supplied monthly differences, rather than describing every month.

Changes in rainfall

Averaged across calendar months, mean daily rainfall had a difference of +0.44 mm/day compared with the earlier reference period. This is an unweighted average of monthly means, and the measure is daily rainfall rather than monthly totals. The largest monthly increase in mean daily rainfall occurred in August, with a difference of +4.33 mm/day. This describes a monthly mean daily amount, not the total rainfall for that month. By contrast, May had the largest monthly decrease, a difference of -1.91 mm/day in mean daily rainfall. These contrasting monthly changes show why the overall average does not describe the difference in every month.

Changes in sunshine duration

Averaged across calendar months, mean daily sunshine duration had a difference of -0.81 hours/day compared with the earlier reference period. This unweighted mean summarizes monthly averages; it is not a day-weighted annual figure. The largest monthly decrease in mean daily sunshine was in June, with a difference of -2.14 hours/day. That monthly result is a specific contrast and should not be taken to mean that sunshine decreased by the same amount in every month.