Climate Change Chart of Seoul, South Korea

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.00 °C compared with the earlier reference period; this is an unweighted average of the monthly means, not a day-weighted annual average or a measure of daytime maximum temperatures. The strongest month-specific increase was in January, with a difference of +2.46 °C. That identifies the largest monthly increase, rather than implying that temperatures rose by the same amount in every month.

Changes in rainfall

Mean daily rainfall, rather than monthly rainfall totals, had a difference of +0.32 mm/day averaged across calendar months. This unweighted mean summarizes the monthly averages and does not mean that rainfall increased in every month. The largest monthly increase occurred in August, at a difference of +2.64 mm/day, while June had the largest decrease, with a difference of -1.90 mm/day. These contrasting monthly differences show why the overall mean should not be read as a uniform change through the year.

Changes in sunshine duration

Mean daily sunshine duration had a difference of -0.18 hours/day averaged across calendar months in the more recent period. This is an unweighted mean across monthly averages, not a day-weighted annual measure, and it does not establish the direction of change in every month. The largest monthly increase was in July, with a difference of +0.78 hours/day; the largest monthly decrease was in August, with a difference of -0.93 hours/day. The opposite directions in these months give useful context for the aggregate mean.

Changes in snowfall

Mean daily snowfall had a difference of -0.06 mm/day averaged across calendar months. This unweighted average of monthly means is not a day-weighted annual total, and the decrease in the mean does not imply a decrease in every month. The largest monthly increase occurred in March, at a difference of +0.26 mm/day, while the largest decrease occurred in January, at a difference of -0.70 mm/day. These month-specific changes describe mean daily amounts, not monthly snowfall totals.