Climate Change Chart of Copenhagen, Denmark

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.96 °C compared with the earlier reference period. This is an unweighted average of monthly means, not a day-weighted annual average, and it does not imply the same change in every month or describe daytime maximum temperatures. The largest monthly increase occurred in January, with a difference of +4.49 °C. This highlights one month’s change rather than a uniform shift throughout the year.

Changes in rainfall

Averaged across calendar months, mean daily rainfall shows a difference of +0.33 mm/day compared with the earlier reference period. This unweighted average of monthly means describes daily amounts, not monthly rainfall totals, and does not mean every month became wetter. The largest monthly increase was in October, where mean daily rainfall had a difference of +1.20 mm/day. By contrast, August had the largest monthly decrease, with a difference of -0.33 mm/day; together, these contrasts show why the overall average does not capture each month’s direction.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, has a difference of +0.04 hours/day. This is an unweighted average of monthly means, not a day-weighted annual figure, and the small average increase does not indicate that sunshine rose in every month. The largest monthly increase was in April, at a difference of +1.27 hours/day, while October recorded the largest monthly decrease, at a difference of -0.87 hours/day. These month-specific changes qualify the modest overall average; sunshine here refers to mean hours per day.

Changes in snowfall

Averaged across calendar months, mean daily snowfall shows a difference of -0.68 mm/day compared with the earlier reference period. This unweighted average of monthly means concerns daily snowfall amounts, not monthly totals, and does not imply that the change was identical in every month. The largest monthly decrease occurred in January, with a difference of -2.54 mm/day in mean daily snowfall. This is a month-specific comparison and should not be read as evidence that snowfall was absent in either period.