Climate Change Chart of Winnipeg, Canada

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.04 °C. This is a comparison of monthly means, not daytime maximum temperatures, and it summarizes the months collectively rather than implying the same change in every month. The largest monthly increase was in December, with a difference of +2.59 °C. In contrast, October had the largest monthly decrease, a difference of -1.25 °C; these month-specific extremes show that the overall mean does not describe every month’s change.

Changes in snowfall

Mean daily snowfall averaged across calendar months had a difference of +0.41 mm/day. This is an unweighted average of monthly means, not an annual total, and does not mean that each month changed by the same amount. The largest monthly increase in mean daily snowfall occurred in October, with a difference of +1.96 mm/day. In March, the largest monthly decrease was a difference of -2.16 mm/day; these opposing changes show why the calendar-month average should not be read as a description of every month.

Changes in rainfall

Mean daily rainfall averaged across calendar months had a difference of 0.00 mm/day. This rounded mean is unchanged, even though individual months differed; it describes an unweighted average of monthly means, not a day-weighted annual total or monthly rainfall totals. The largest monthly decrease in mean daily rainfall occurred in June, at a difference of -0.79 mm/day, while August recorded the largest increase, a difference of +0.30 mm/day. These daily-mean comparisons identify contrasting monthly changes without implying that rainfall moved in the same direction in every month.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, had a difference of -0.16 hours/day. This aggregate describes the average of the calendar-month means, rather than a day-weighted annual figure or a uniform shift in sunshine throughout the year. The largest monthly increase was in June, with a difference of +1.16 hours/day; the largest decrease was in October, at a difference of -1.10 hours/day. These month-specific differences provide context for the mean while making clear that it does not represent every month’s daily sunshine duration.