Climate Change Chart of Changsha, China

Overview of climate changes

Changes in rainfall

Mean daily rainfall averaged across calendar months had a difference of -0.42 mm/day compared with the earlier reference period; this is an unweighted comparison of monthly means, not a change in monthly totals or a day-weighted annual average. The largest monthly increase occurred in July, with a difference of +1.89 mm/day, whereas the largest monthly decrease was in April, with a difference of -1.93 mm/day. Those monthly contrasts qualify the overall mean: it does not imply the same change in every month, nor describe day-to-day variability.

Changes in sunshine duration

Averaged across calendar months, mean daily sunshine duration had a difference of -0.45 hours/day in the more recent period. This unweighted comparison of monthly means is not a day-weighted annual average and does not indicate that every month shifted by the same amount. The largest monthly decrease was in July, at -0.97 hours/day, while December had the largest monthly increase, at +0.47 hours/day. The opposing monthly differences provide context for the overall mean, but do not establish a continuous change between the reference periods or describe daily variability.

Changes in snowfall

Mean daily snowfall, averaged across calendar months, had a difference of -0.08 mm/day; this unweighted mean comparison is not a monthly total or a day-weighted annual average. The largest monthly decrease occurred in February, with a difference of -1.19 mm/day, while the largest monthly increase was in January, at +0.15 mm/day. These differences describe changes in monthly mean amounts, not snowfall on every day, and the comparison does not imply that snowfall was absent in either period.

Temperature changes

Averaged across calendar months, the difference in monthly mean temperature was -0.03 °C; this unweighted comparison describes the means across months, not a continuous trend or daytime maximum temperatures. The largest monthly increase was in August, at +0.67 °C, while the largest monthly decrease was in May, at -0.52 °C. These contrasting monthly differences show that the overall mean change does not describe every month individually.