Climate Change Chart of Pago Pago, American Samoa

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +0.63 °C compared with the earlier reference period. This is an unweighted mean of the monthly means, not a day-weighted annual average, and it describes the aggregate rather than every month; these temperatures are not daytime maximum temperatures. The largest monthly increase was in November, with a difference of +0.89 °C. That identifies the strongest increase among the supplied monthly temperature differences, rather than implying that all months changed by the same amount.

Changes in rainfall

Averaged across calendar months, mean daily rainfall had a difference of +1.63 mm/day compared with the earlier reference period. This unweighted mean summarizes the monthly means; it is not a day-weighted annual average, and the daily amounts should not be read as monthly rainfall totals. The largest monthly increase in mean daily rainfall occurred in January, at a difference of +4.98 mm/day. By contrast, the largest monthly decrease was in July, with a difference of -0.21 mm/day. These extrema show that monthly differences were not uniform, while referring to daily mean amounts rather than monthly totals.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, had a difference of -0.44 hours/day compared with the earlier reference period. This is an unweighted mean of monthly means, not a day-weighted annual average, and it does not mean that every month had the same difference. The largest monthly decrease in mean daily sunshine duration occurred in January, with a difference of -1.19 hours/day. This marks the strongest monthly decrease among the supplied differences, without describing all months or establishing a continuous trend between the reference periods.