Climate Change Chart of Victoria, Canada

Overview of climate changes

Temperature changes

Across the calendar months, monthly mean temperatures show a mean difference of +0.95 °C in the more recent reference period. This is an unweighted average of the monthly means, not a day-weighted annual figure, and it does not mean every month warmed by the same amount. The largest monthly increase was in January, with a difference of +2.38 °C; these are monthly mean temperatures, not daytime maximums.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of -0.32 hours/day in the more recent period; this unweighted average of monthly means does not imply the same change in every month. The largest monthly decrease was in September, with a difference of -0.81 hours/day. By contrast, the largest increase was in August, at a difference of +0.02 hours/day. These are differences in mean daily hours, rather than totals for a month.

Changes in rainfall

Averaged across calendar months, mean daily rainfall had a difference of +0.07 mm/day in the more recent period. This unweighted mean of monthly means describes an overall comparison, not a daily amount for every month or a monthly total. The month with the largest increase was January, at a difference of +1.42 mm/day, while the largest decrease occurred in February, with a difference of -0.62 mm/day. These contrasts show that the monthly changes were not uniform.

Changes in snowfall

For mean daily snowfall, the unweighted average of monthly means had a difference of -0.23 mm/day across calendar months in the more recent period. This overall comparison does not describe every month or represent monthly snowfall totals. The largest monthly decrease was in January, with a difference of -3.00 mm/day, whereas the largest increase occurred in December, at a difference of +0.79 mm/day. The contrasting monthly changes make clear that the mean difference should not be read as a uniform shift throughout the calendar.