Climate Change Chart of Sapporo, Japan

Overview of climate changes

Changes in snowfall

Mean daily snowfall averaged across calendar months had a difference of +0.52 mm/day in the more recent period, based on an unweighted comparison of monthly means. The largest monthly increase was in January, with a difference of +4.48 mm/day, whereas April showed the largest decrease, at a difference of -1.43 mm/day. These figures refer to mean daily snowfall, not monthly totals; the average across calendar months does not imply the same change in every month.

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +0.90 °C compared with the earlier reference period; this is an unweighted comparison of monthly means, not a day-weighted annual average or a measure of daytime highs. The largest monthly increase was in May, with a difference of +2.57 °C. By contrast, August had the largest monthly decrease, at a difference of -0.31 °C. These month-specific differences show that the overall mean does not describe every month.

Changes in rainfall

Mean daily rainfall averaged across calendar months had a difference of +0.59 mm/day in the more recent period, an unweighted mean of monthly averages rather than a day-weighted annual total. The largest monthly increase was in August, where mean daily rainfall had a difference of +2.65 mm/day. The largest decrease occurred in September, at a difference of -0.10 mm/day. These figures describe average daily amounts within the relevant months, not monthly rainfall totals, and the overall mean should not be taken to apply equally to each month.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of -0.40 hours/day compared with the earlier reference period; this is an unweighted comparison of monthly means. The monthly pattern was not uniform: July recorded the largest increase, with a difference of +0.75 hours/day, while August had the largest decrease, at a difference of -1.15 hours/day. These are differences in mean daily hours, not totals of sunshine accumulated over each month.