Climate Change Chart of Vienna, Austria

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +2.11 °C compared with the earlier reference period; this is an unweighted mean of monthly means, not a day-weighted annual average or a measure of daytime highs. The month-to-month pattern was not uniform: January had the largest monthly increase, a difference of +5.28 °C, while September had the largest monthly decrease, a difference of -0.02 °C. These extrema describe the largest changes in their respective directions, rather than a change shared by every month.

Changes in snowfall

Mean daily snowfall, averaged across calendar months, shows a difference of -0.82 mm/day; this is an unweighted comparison of monthly means, not a total snowfall amount. The largest monthly decrease was in January, with a difference of -2.72 mm/day. This monthly change need not represent the direction or size of the difference in every other month.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, shows a difference of -0.31 hours/day; this is an unweighted summary of monthly means, not an annual total. Monthly differences ran in both directions: June recorded the largest increase, a difference of +0.51 hours/day, while January recorded the largest decrease, a difference of -1.05 hours/day. These figures describe changes in average daily sunshine for the specified months and do not establish that the same pattern occurred throughout the year.

Changes in rainfall

Mean daily rainfall, rather than monthly rainfall totals, averaged across calendar months shows a difference of +0.35 mm/day. That unweighted average summarizes the monthly means and does not imply that rainfall increased in every month. The largest monthly increase was in September, with a difference of +1.33 mm/day; in contrast, July had the largest monthly decrease, a difference of -0.53 mm/day. The monthly extremes therefore show variation in the direction and size of the period differences, not a uniform change in daily rainfall.