Climate Change Chart of Jefferson City, USA

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.02 °C in the more recent reference period; this is an unweighted comparison of monthly means, not a day-weighted annual average or a measure of daytime highs. The largest monthly increase was in December, with a difference of +2.08 °C compared with the earlier period. In contrast, October had the largest monthly decrease, a difference of -0.33 °C. These month-specific changes show that the overall mean does not describe every calendar month.

Changes in snowfall

Mean daily snowfall averaged across calendar months had a difference of -0.28 mm/day, a decrease in the more recent reference period; this is an unweighted mean of monthly means, not a total snowfall difference. The monthly pattern includes opposing changes: March had the largest decrease, a difference of -2.37 mm/day, while February had the largest increase, a difference of +0.41 mm/day. These are changes in mean daily amounts and do not imply the same difference for every day or month.

Changes in rainfall

Mean daily rainfall, rather than monthly totals, was higher on average across calendar months, with a difference of +0.34 mm/day between the reference periods. The increase was not uniform across the monthly comparisons: July recorded the largest monthly increase, a difference of +1.10 mm/day, while May had the largest decrease, a difference of -0.18 mm/day. These differences describe changes in the monthly mean daily amounts and should not be read as changes applying to every day or as a continuous trend.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of -0.16 hours/day in the more recent period. At the monthly extremes, September had the largest increase, a difference of +0.44 hours/day, whereas October had the largest decrease, a difference of -0.73 hours/day. The average summarizes monthly means, so it does not imply that daily sunshine changed in the same direction in every month.