Climate Change Chart of Chiba, Japan

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +0.72 °C compared with the earlier reference period; this unweighted comparison describes the monthly means collectively, not a change in daytime maximum temperatures or a continuous trend. March had the largest monthly increase, a difference of +1.59 °C, while January had the largest monthly decrease, a difference of -0.38 °C. These month-specific contrasts show that the overall mean difference does not describe every month equally.

Changes in rainfall

Mean daily rainfall, rather than monthly totals, averaged across calendar months, shows a difference of +1.00 mm/day between the reference periods. The largest monthly increase was in July, with a difference of +2.66 mm/day; by contrast, November recorded the largest monthly decrease, a difference of -0.23 mm/day. These monthly mean differences describe typical daily amounts within each calendar month and should not be read as changes in every individual day or as a continuous trend.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months shows a difference of -0.30 hours/day in the more recent period. This unweighted summary of monthly means does not imply the same change in each month. The largest monthly increase occurred in November, with a difference of +0.38 hours/day, whereas the largest monthly decreases were tied across July / September, each with a difference of -0.69 hours/day. These are differences in average daily sunshine hours, not a measure of how sunshine changed from day to day.

Changes in snowfall

Mean daily snowfall averaged across calendar months shows a difference of +0.18 mm/day between the reference periods. This is an unweighted comparison of monthly means, not a monthly total, and it does not establish that snowfall changed by the same amount in every month. The largest monthly increase was in February, with a difference of +1.57 mm/day, while December had the largest monthly decrease, a difference of -0.08 mm/day. These differences describe recorded snowfall averages at the stated precision; they do not indicate the presence or absence of snowfall on particular days.