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 an unweighted comparison of monthly means, not a day-weighted annual average, and it does not describe every month or daytime highs. The largest monthly increase was in December, with a difference of +2.86 °C. By contrast, October had the largest decrease, a difference of -0.36 °C; these are monthly averages, not a measure of day-to-day variability.

Changes in rainfall

Mean daily rainfall averaged across calendar months had a difference of +0.39 mm/day. This summarizes the monthly averages rather than monthly rainfall totals, and does not mean every month became wetter. The largest monthly increase in mean daily rainfall occurred in October, with a difference of +1.16 mm/day. That difference describes the daily mean for that month; it cannot establish how many rainy days occurred or how rainfall was distributed from day to day.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, had a difference of -0.19 hours/day. The monthly pattern was not uniform: June recorded the largest increase, a difference of +0.93 hours/day, while October had the largest decrease, a difference of -1.44 hours/day.

Changes in snowfall

Mean daily snowfall averaged across calendar months had a difference of -0.18 mm/day. The largest monthly increase was in February, with a difference of +2.24 mm/day, while the largest decrease was in March, with a difference of -1.41 mm/day. These are daily means, not monthly snowfall totals, and do not indicate conditions on particular dates.