Climate Change Chart of Tampere, Finland

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.97 °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 maximum temperatures. The largest monthly increase was in January, with a difference of +4.75 °C. By contrast, July had the largest monthly decrease, a difference of -0.01 °C; these selected months do not describe every month's change.

Changes in snowfall

Mean daily snowfall averaged across calendar months shows a difference of +0.31 mm/day. This is an unweighted average of monthly means, not an annual total, and the monthly mean difference does not establish the change in every month. The largest monthly increase was in January, with a difference of +2.78 mm/day; the largest decrease was in November, with a difference of -1.34 mm/day. These describe daily snowfall means, not monthly snowfall totals.

Changes in rainfall

Mean daily rainfall, rather than monthly rainfall totals, averaged across calendar months shows a difference of +0.28 mm/day. This unweighted monthly-mean comparison summarizes the overall difference without implying that rainfall changed by the same amount in every month. The largest monthly increase was in August, at a difference of +0.70 mm/day, while September recorded the largest monthly decrease, at a difference of -0.42 mm/day. These daily-mean differences are not monthly totals.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of -0.17 hours/day compared with the earlier period. This is an unweighted mean of monthly values, not a day-weighted annual average, and does not mean that daily sunshine changed uniformly throughout the year. Monthly differences varied in direction: June had the largest increase, a difference of +0.77 hours/day, whereas July had the largest decrease, a difference of -1.02 hours/day.