Climate Change Chart of Puerto Rico, Puerto Rico

Overview of climate changes

Changes in rainfall

Averaged across calendar months, mean daily rainfall had a difference of -0.45 mm/day in the more recent period. This is an unweighted summary of monthly means, not a day-weighted annual average or a monthly rainfall total, and it does not imply that rainfall decreased in every month. The largest monthly decrease occurred in October, with a difference of -1.58 mm/day; by contrast, March had the largest monthly increase, at +0.59 mm/day. These contrasting monthly differences show why the average should not be read as a description of each month's change.

Temperature changes

Averaged across calendar months, monthly mean temperature showed a difference of +0.79 °C compared with the earlier reference period; this unweighted summary describes the average of the monthly means, not daytime maximum temperatures or the change in every month. The largest monthly increase was in June, at +1.04 °C, so that month marks the strongest increase in this comparison, not a uniform change throughout the year.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, had a difference of -0.09 hours/day compared with the earlier reference period. This unweighted average of monthly means is not a measure of how every month changed. The largest monthly decrease was in November, with a difference of -0.40 hours/day, while the largest monthly increase came in May, at +0.25 hours/day. These monthly contrasts describe changes in average daily sunshine, rather than total sunshine over a month.