Climate Change Chart of Apia, Samoa

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +0.28 °C compared with the earlier reference period; this is an unweighted mean of monthly means, not a day-weighted annual average or a continuous trend. The largest monthly increase was in November, with a difference of +0.60 °C. By contrast, August had the largest monthly decrease, a difference of -0.01 °C. These figures describe monthly mean temperatures, not daytime maxima.

Changes in rainfall

Averaged across calendar months, mean daily rainfall had a difference of +0.99 mm/day compared with the earlier reference period. This unweighted mean of monthly means describes daily amounts, not monthly rainfall totals, and does not imply that rainfall increased in every month. The largest monthly increase was in January, at a difference of +6.06 mm/day, while October recorded the largest monthly decrease, a difference of -1.61 mm/day. These contrasting monthly changes show why the overall mean should be read alongside the month-specific differences.

Changes in sunshine duration

Mean daily sunshine duration had an unweighted difference of -0.42 hours/day averaged across calendar months, compared with the earlier reference period; this is not a day-weighted annual average or evidence of a continuous change. The largest monthly decrease occurred in February, with a difference of -1.20 hours/day. That month-specific result is distinct from the mean across months and does not establish that sunshine decreased by the same amount in every month.