Climate Change Chart of Vancouver, Canada

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.23 °C compared with the earlier reference period; this unweighted comparison describes the monthly means collectively, not daytime maximum temperatures or a change shared by every month. The largest monthly increase was in January, with a difference of +3.64 °C. This identifies the strongest increase among the supplied monthly temperature differences, rather than implying that every month warmed by the same amount.

Changes in rainfall

Averaged across calendar months, mean daily rainfall increased by +0.34 mm/day. This is an unweighted mean of monthly mean daily amounts, not a day-weighted annual average or a monthly rainfall total. The largest monthly increase in mean daily rainfall was in November, a difference of +2.34 mm/day. By contrast, February had the largest monthly decrease, with a difference of -1.49 mm/day; these contrasting monthly changes show why the overall mean does not describe every month.

Changes in snowfall

Averaged across calendar months, mean daily snowfall increased by +0.03 mm/day. The difference is small at the displayed precision, but it still records a change in the unweighted monthly means; it does not establish that snowfall was absent or unchanged beyond that precision. Monthly differences varied: December had the largest increase in mean daily snowfall, at +1.24 mm/day, while January had the largest decrease, at -2.65 mm/day. These are daily mean amounts, not monthly totals, and the opposing monthly differences are not captured by the overall mean alone.

Changes in sunshine duration

Mean daily sunshine duration, averaged across calendar months, shows a difference of -0.46 hours/day compared with the earlier reference period. This unweighted mean summarizes monthly average daily hours; it does not mean that sunshine declined by the same amount in every month. The largest monthly decrease in mean daily sunshine duration occurred in September, with a difference of -0.99 hours/day. This monthly contrast is distinct from the across-month mean and should not be read as a description of all months.