Climate Change Chart of Zurich, Switzerland

Overview of climate changes

Temperature changes

Monthly mean temperatures show an average difference of +1.64 °C across calendar months in the more recent 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 January, with a difference of +4.16 °C compared with the earlier reference period. By contrast, May had the largest monthly decrease, a difference of -0.16 °C; these monthly extremes do not imply the same change in every month.

Changes in snowfall

Mean daily snowfall, averaged across calendar months, had a difference of -0.43 mm/day in the more recent period. This is an unweighted comparison of monthly means, not an annual total; the difference alone does not show how snowfall changed in every month. The largest monthly decrease occurred in February, with a difference of -1.63 mm/day compared with the earlier reference period. In April, mean daily snowfall instead had the largest monthly increase, a difference of +0.93 mm/day. Together, these monthly extrema show that snowfall differences varied by month, without implying conditions beyond the measured monthly averages.

Changes in rainfall

Mean daily rainfall averaged across calendar months had a difference of +0.89 mm/day in the more recent period. This is an unweighted mean of monthly averages, not an annual total or a day-weighted annual average. The largest monthly increase occurred in July, where mean daily rainfall had a difference of +1.53 mm/day compared with the earlier reference period; it describes the daily mean for that month, not its monthly accumulation.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of -0.53 hours/day in the more recent period. This unweighted comparison of monthly means does not establish that sunshine duration decreased in every month. The largest monthly decrease was in January, with a difference of -0.77 hours/day compared with the earlier reference period.