Climate Change Chart of Charleston, USA

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.12 °C in the more recent period. This is an unweighted comparison of the calendar-month means, not a day-weighted annual average, and it describes monthly means rather than daytime maximum temperatures. The largest monthly increase was in December, with a difference of +2.69 °C compared with the earlier reference period. This identifies the strongest increase among the monthly means, not a uniform change across every month.

Changes in rainfall

Averaged across calendar months, mean daily rainfall had a difference of +0.23 mm/day in the more recent period. This unweighted mean of monthly means describes daily rainfall amounts, not monthly rainfall totals, and does not imply that every month changed in the same direction. The largest monthly increase occurred in February, with a difference of +1.26 mm/day in mean daily rainfall. By contrast, November had the largest monthly decrease, a difference of -0.81 mm/day; these are the most pronounced monthly changes in opposite directions, not a description of all months.

Changes in sunshine duration

Averaged across calendar months, mean daily sunshine duration had a difference of -0.22 hours/day in the more recent period. This unweighted comparison summarizes the monthly mean daily hours, rather than indicating the same change in every month. The largest monthly decrease was in March, with a difference of -0.71 hours/day in mean daily sunshine duration. The largest monthly increase came in November, at a difference of +0.34 hours/day, showing that the month-to-month comparisons did not all move in one direction.

Changes in snowfall

Averaged across calendar months, mean daily snowfall had a difference of -0.06 mm/day in the more recent period. This is an unweighted comparison of monthly means and refers to daily snowfall amounts, not monthly totals; the average alone does not describe every month's change. The largest monthly decrease was in December, with a difference of -1.39 mm/day in mean daily snowfall. In February, the largest monthly increase was a difference of +0.96 mm/day, so the monthly changes included movement in both directions.