Climate Change Chart of Glasgow, Great Britain

Overview of climate changes

Temperature changes

Averaged across calendar months, the difference in monthly mean temperature was +0.38 °C compared with the earlier reference period; this is an unweighted mean of monthly means, not a day-weighted annual average or a measure of daytime maximum temperatures. The largest monthly increase was in January, at a difference of +1.44 °C, while April had the largest monthly decrease, with a difference of -0.53 °C.

Changes in rainfall

Mean daily rainfall, averaged across calendar months, had a difference of +0.63 mm/day in the more recent period; this unweighted comparison of monthly means describes daily amounts rather than monthly rainfall totals. The largest monthly increase occurred in December, with a difference of +1.61 mm/day, whereas April recorded the largest decrease, at a difference of -1.03 mm/day. These monthly differences describe changes in mean daily rainfall, not the rainfall on every day.

Changes in sunshine duration

Averaged across calendar months, mean daily sunshine duration showed a difference of -0.20 hours/day compared with the earlier reference period. This is an unweighted comparison of monthly mean daily hours, rather than a day-weighted annual measure. April had the largest monthly increase, with a difference of +0.59 hours/day; the largest monthly decrease was in May, at a difference of -0.91 hours/day.

Changes in snowfall

The unweighted mean difference in mean daily snowfall, averaged across calendar months, was -0.22 mm/day. This describes the average of monthly mean daily amounts, not monthly snowfall totals. The largest monthly decrease was in January, with a difference of -1.88 mm/day, while April had the largest increase, at a difference of +0.35 mm/day. The monthly comparisons refer to mean daily snowfall and do not imply the same change on each day.