Climate Change Chart of Concord, USA

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +0.70 °C compared with the earlier reference period; this is an unweighted average of monthly means, not a day-weighted annual average or a measure of daytime highs. The monthly differences were not uniform: December had the largest increase, a difference of +1.98 °C, while November had the largest decrease, a difference of -0.91 °C. These extrema describe the changes in those months, not every month’s conditions.

Changes in snowfall

Mean daily snowfall averaged across calendar months had a difference of +0.16 mm/day; this is an unweighted average of monthly means, not a monthly total or day-weighted annual average. The monthly differences varied in direction: December had the largest increase, a difference of +2.16 mm/day, while January had the largest decrease, a difference of -1.96 mm/day. These comparisons concern recorded mean daily snowfall and do not imply the same change in every month.

Changes in rainfall

Mean daily rainfall, rather than monthly totals, was higher on average across calendar months, with a difference of +0.23 mm/day. This unweighted mean summarizes the monthly averages and does not imply that rainfall rose in each month. The largest monthly increase was in October, at a difference of +1.57 mm/day, whereas November recorded the largest decrease, a difference of -1.05 mm/day. Together, these monthly contrasts show why the overall average should not be read as a uniform change throughout the year.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of -0.20 hours/day compared with the earlier period; the figure is an unweighted average of monthly means, not a day-weighted annual total. The monthly pattern varied: May had the largest increase, a difference of +0.94 hours/day, while October / December shared the largest decrease, with a difference of -0.99 hours/day. The decrease therefore applies to both listed months, and the mean change does not describe sunshine in every individual month.