Climate Change Chart of Jeju City, South Korea

Overview of climate changes

Temperature changes

Averaged across calendar months, the monthly mean temperature difference was +0.71 °C compared with the earlier reference period. This is an unweighted comparison of monthly means, not a day-weighted annual average, and it describes average temperatures rather than daytime highs. The largest monthly increase was in March, at a difference of +1.37 °C; by contrast, December had the largest decrease, with a difference of -0.02 °C. These extrema show that the comparison was not uniform across months.

Changes in rainfall

Mean daily rainfall, rather than monthly rainfall totals, was higher by +1.36 mm/day on average across calendar months in the more recent period. This is an unweighted mean of the monthly differences, so it does not imply the same change in every month. The largest increase occurred in September, with a difference of +5.43 mm/day, while June recorded the largest decrease, a difference of -1.23 mm/day. The contrast between those monthly extremes underscores the variation in how daily rainfall averages differed between the reference periods.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of -0.38 hours/day, a decrease compared with the earlier reference period. This unweighted monthly average summarizes the overall direction without suggesting that sunshine fell in every month. The largest monthly decrease was in April, at a difference of -0.84 hours/day; in July, sunshine instead had its largest increase, with a difference of +0.12 hours/day. These monthly contrasts qualify the overall decrease and describe daily mean hours, not total sunshine accumulated over a month.

Changes in snowfall

Mean daily snowfall, not monthly snowfall totals, differed by an average of +0.82 mm/day across calendar months, an unweighted comparison of monthly means. The largest monthly increase was in December, with a difference of +4.23 mm/day; the largest decrease came in March, at a difference of -0.04 mm/day. The overall mean and these contrasting monthly changes describe differences in recorded snowfall averages between the reference periods; they do not establish that the same change occurred throughout the year.