Climate Change Chart of Whitefish Mountain, USA

Overview of climate changes

Temperature changes

The mean difference in monthly mean temperatures, averaged across calendar months, was an increase of +1.28 °C compared with the earlier reference period; this unweighted comparison of month means does not describe daytime maximum temperatures or imply the same change in every month. The largest monthly increase was in January, with a difference of +4.15 °C. By contrast, October had the largest monthly decrease, a difference of -0.27 °C, showing that the month-to-month comparison was not uniform.

Changes in snowfall

Mean daily snowfall, averaged across calendar months, showed a decrease of -2.12 mm/day in the more recent period. This unweighted mean describes differences between monthly averages, not a day-weighted annual amount or a change shared by every month. The largest monthly decrease was in November, with a difference of -6.09 mm/day. In contrast, the largest monthly increase occurred in June, at a difference of +0.06 mm/day; both figures concern mean daily snowfall, not monthly totals.

Changes in rainfall

Mean daily rainfall, averaged across calendar months, had a small increase of +0.04 mm/day in the more recent period. This is an unweighted mean of monthly averages, not a change in annual rainfall totals, and it does not mean that rainfall rose in every month. The most pronounced monthly increase was in March, at a difference of +0.64 mm/day, while June recorded the largest decrease, a difference of -0.60 mm/day. These figures describe mean daily amounts for those months rather than monthly rainfall totals.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months was lower by a difference of -0.11 hours/day compared with the earlier reference period. This unweighted summary of monthly means does not imply an equal reduction on each day or in every month. The largest monthly increase occurred in June, with a difference of +0.68 hours/day; the largest decrease was in April, at a difference of -0.55 hours/day. These contrasting monthly differences put the overall mean in context without suggesting a uniform pattern through the year.