Climate Change Chart of St. Thomas, Virgin Islands (U.S.)

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature was higher by a difference of +0.71 °C in the more recent period; this is an unweighted comparison of monthly means, not a day-weighted annual average or a measure of daytime maximum temperatures. The largest monthly increase was in September, with a difference of +1.00 °C. This identifies the strongest increase among the supplied monthly comparisons, rather than describing every month or a continuous change through time.

Changes in rainfall

Averaged across calendar months, mean daily rainfall was lower by a difference of -0.80 mm/day compared with the earlier reference period. This unweighted mean of monthly means summarizes the comparison across calendar months; it is not a monthly rainfall total, and it does not imply that rainfall decreased in every month. The largest monthly decrease in mean daily rainfall occurred in October, at a difference of -2.12 mm/day. That marks the strongest decrease in the supplied monthly comparisons, not a change in monthly totals.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, was lower by a difference of -0.05 hours/day in the more recent period. This is an unweighted comparison of monthly means, rather than a day-weighted annual average, and the small mean difference does not imply the same change in each month. Monthly differences varied in direction: the largest increase was in September, at a difference of +0.20 hours/day, while the largest decrease was in July, at a difference of -0.35 hours/day. These are comparisons of mean daily sunshine, not changes in total monthly sunshine.