Climate Change Chart of Saint Paul, USA

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.08 °C compared with the earlier reference period; this is an unweighted mean of the monthly means, not a day-weighted annual average or a measure of daytime highs. The largest monthly increases were tied in June / September, each with a difference of +2.21 °C. By contrast, October had the largest monthly decrease, a difference of -0.86 °C.

Changes in rainfall

Averaged across calendar months, mean daily rainfall had a difference of +0.36 mm/day in the more recent period; this unweighted comparison of monthly means is not a day-weighted annual average. The largest monthly increase occurred in October, with a difference of +1.16 mm/day, while June recorded the largest decrease, a difference of -0.37 mm/day. These figures describe daily mean amounts, not monthly rainfall totals, and the month-specific changes show that the overall mean does not describe every month.

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 average of monthly means, rather than a day-weighted annual measure. The clearest monthly contrast was between June, which had the largest increase at +1.30 hours/day, and October, which had the largest decrease at -1.04 hours/day. The calendar-month average summarizes those monthly comparisons and should not be read as the change in every month.

Changes in snowfall

Averaged across calendar months, mean daily snowfall had a difference of +0.40 mm/day between the reference periods; this is an unweighted mean of monthly means, not a day-weighted annual average. The largest monthly increase was in April, with a difference of +2.87 mm/day, while the largest decrease occurred in March, at -1.76 mm/day. These are daily mean amounts rather than monthly totals, and the overall mean does not imply that snowfall changed in the same direction in every month.