Climate Change Chart of Halifax, Canada

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.28 °C compared with the earlier reference period; this is an unweighted mean of the monthly means, not a day-weighted annual average or a measure of daytime maximum temperatures. The largest monthly increase was in January, with a difference of +2.51 °C. This identifies the strongest increase among the supplied monthly comparisons, rather than indicating that every month changed by the same amount.

Changes in rainfall

Averaged across calendar months, mean daily rainfall has a difference of +0.73 mm/day in the more recent period. This is an unweighted summary of monthly means, not a day-weighted annual average, and the daily measure should not be read as a monthly rainfall total. The largest monthly increase in mean daily rainfall occurred in December, at a difference of +2.17 mm/day. By contrast, May had the largest monthly decrease, with a difference of -0.58 mm/day; these are the strongest opposing monthly changes in the supplied comparisons, not a description of every month.

Changes in sunshine duration

Averaged across calendar months, mean daily sunshine duration shows a difference of -0.27 hours/day compared with the earlier reference period. This unweighted average summarizes the monthly means and does not imply the same change in each month. The largest monthly decrease was in January, with a difference of -0.73 hours/day, while May recorded the largest monthly increase, at a difference of +0.30 hours/day. These monthly extremes show that the changes were not uniform across the calendar.

Changes in snowfall

Averaged across calendar months, mean daily snowfall increased by a difference of +0.48 mm/day in the more recent period. This is an unweighted mean of monthly means; the daily amounts are not monthly totals, and the aggregate change does not describe each month's conditions. The largest monthly increase in mean daily snowfall occurred in March, with a difference of +5.73 mm/day. The largest monthly decrease was in December, at a difference of -0.92 mm/day, illustrating contrasting monthly changes without implying that snowfall was absent in either period.