Climate Change Chart of Hartford, USA

Overview of climate changes

Changes in snowfall

Mean daily snowfall was lower by a difference of -0.23 mm/day when the monthly means are averaged across calendar months. This unweighted summary does not describe monthly totals or imply the same change in every month. The largest monthly decrease was in January, with a difference of -3.35 mm/day, while March had the largest increase, a difference of +0.73 mm/day. The monthly contrasts therefore include both decreases and an increase, alongside the lower aggregate mean.

Temperature changes

The unweighted mean difference across calendar months indicates that monthly mean temperature was higher by a difference of +0.70 °C in the more recent period; this summarizes the calendar-month averages and is not a statement about every month or about daytime highs. The largest monthly increase was in December, with a difference of +2.17 °C. By contrast, November had the largest monthly decrease, a difference of -0.66 °C.

Changes in rainfall

Averaged across calendar months, mean daily rainfall was higher by a difference of +0.36 mm/day; this unweighted summary of monthly means is not a day-weighted annual average or a monthly total. The largest monthly increase occurred in September, at a difference of +1.65 mm/day, while May recorded the largest decrease, a difference of -0.89 mm/day. These monthly contrasts show that the aggregate increase did not apply uniformly across the calendar months.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, was lower by a difference of -0.22 hours/day in the more recent period. This is an unweighted summary of monthly mean daily hours, not a measure of every day. The largest monthly increase was in May, with a difference of +0.76 hours/day, whereas October had the largest decrease, a difference of -0.99 hours/day.