Climate Change Chart of Pierre, USA

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +0.79 °C. This is an unweighted comparison of monthly means, not a day-weighted annual average or a statement about daytime highs. The largest monthly increase was in June, with a difference of +2.78 °C; by contrast, October had the largest monthly decrease, a difference of -1.09 °C. These monthly differences show that the comparison varies by month rather than describing a uniform shift.

Changes in snowfall

Snowfall is represented here by mean daily amounts, not monthly totals. Averaged across calendar months, the unweighted mean difference was +0.33 mm/day. At the monthly level, December had the largest increase, with a difference of +3.79 mm/day, whereas January had the largest decrease, a difference of -1.53 mm/day. The positive overall mean and these contrasting monthly changes summarize the period comparison without implying a consistent change in every month.

Changes in rainfall

Mean daily rainfall, rather than monthly rainfall totals, averaged across calendar months shows a difference of -0.04 mm/day. This unweighted mean summarizes the monthly comparisons and does not imply the same change in every month. The largest monthly increase was in May, where mean daily rainfall had a difference of +0.55 mm/day. In June, it had the largest monthly decrease, a difference of -0.82 mm/day. The opposing monthly differences make clear why the overall mean should not be read as a description of each month's rainfall.

Changes in sunshine duration

For mean daily sunshine duration, the unweighted average across calendar months had a difference of -0.02 hours/day. This compact mean difference does not mean that every month's daily sunshine changed by the same amount. The largest increase was in June, with a difference of +1.65 hours/day, while December recorded the largest decrease, a difference of -0.72 hours/day. These are differences in monthly mean daily hours, not totals accumulated over a month.