Climate Change Chart of Pierre, USA

Overview of climate changes

Temperature changes

Across calendar months, the unweighted mean of monthly mean temperatures is higher by +0.79 °C in the more recent reference period; this summarizes the monthly averages, not daytime highs or a change experienced in every month. June records the largest monthly mean temperature increase, a difference of +2.78 °C, while October has the largest decrease, a difference of -1.09 °C. These contrasting monthly results show why the overall mean should not be read as a uniform change through the calendar.

Changes in rainfall

Mean daily rainfall averaged across calendar months is lower by -0.04 mm/day; this is an unweighted summary of monthly means, not a daily or monthly total and not evidence that every month became drier. The largest monthly rainfall increase is in May, with a difference of +0.55 mm/day, whereas June has the largest decrease, a difference of -0.82 mm/day. These are changes in mean daily amounts for those months, not counts of rainy days.

Changes in sunshine duration

Mean daily sunshine averaged across calendar months is lower by -0.02 hours/day. Within that broad average, June has the largest increase, a difference of +1.65 hours/day, while December has the largest decrease, a difference of -0.72 hours/day.