Climate Change Chart of Madison, USA

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.20 °C compared with the earlier reference period. This is a comparison of the unweighted monthly means, not a day-weighted annual average or a measure of daytime maximum temperatures. The largest monthly mean temperature increase was in December, at a difference of +2.86 °C. By contrast, October had the largest decrease, with a difference of -0.36 °C; these monthly extremes show that the mean change was not uniform across the calendar.

Changes in snowfall

Averaged across calendar months, mean daily snowfall had a difference of -0.18 mm/day compared with the earlier reference period. This unweighted summary concerns daily snowfall amounts, not monthly totals, and does not mean the change was the same in every month. The largest monthly increase in mean daily snowfall was in February, with a difference of +2.24 mm/day. The largest decrease occurred in March, at a difference of -1.41 mm/day, showing contrasting monthly differences within the comparison.

Changes in rainfall

Mean daily rainfall, averaged across calendar months, had a difference of +0.39 mm/day compared with the earlier reference period. This summarizes the unweighted monthly means and describes daily amounts, not monthly rainfall totals. The largest monthly increase in mean daily rainfall occurred in October, with a difference of +1.16 mm/day. That monthly contrast highlights where the increase was most pronounced, rather than implying that rainfall rose by the same amount in every month.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of -0.19 hours/day compared with the earlier reference period. This is an unweighted summary of monthly means, not a day-weighted annual average. The largest increase in mean daily sunshine was in June, at a difference of +0.93 hours/day. In contrast, October recorded the largest decrease, with a difference of -1.44 hours/day, indicating that the overall mean does not describe every month's change.