Climate Change Chart of Basel, Switzerland

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.68 °C in the more recent period; this is an unweighted mean of monthly averages, not a day-weighted annual figure or a description of every month. The largest monthly increase was in January, with a difference of +3.95 °C compared with the earlier reference period. These are monthly means, not daytime maximum temperatures.

Changes in snowfall

Mean daily snowfall, averaged across calendar months, shows a difference of -0.54 mm/day compared with the earlier reference period. This unweighted mean summarizes monthly averages; it does not mean that every month changed by the same amount. The largest monthly decrease was in January, with a difference of -2.31 mm/day, while the largest monthly increase occurred in April, at a difference of +0.49 mm/day. These are daily mean amounts, not monthly snowfall totals.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months shows a difference of -0.50 hours/day in the more recent period. This is an unweighted mean of monthly averages, so it does not imply the same change in every month. The largest monthly decrease was in January, with a difference of -1.03 hours/day; by comparison, the largest monthly increase was in February, at a difference of +0.02 hours/day. The figures concern mean daily sunshine hours, not monthly totals.

Changes in rainfall

Mean daily rainfall, averaged across calendar months, increased by a difference of +0.70 mm/day; this unweighted mean describes the set of monthly averages rather than each month individually. The largest monthly increase occurred in October, at a difference of +1.41 mm/day. In contrast, September recorded the largest monthly decrease, a difference of -0.07 mm/day. These figures describe daily mean amounts, not monthly rainfall totals.