Climate Change Chart of Coimbra, Portugal

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +0.48 °C compared with the earlier reference period; this is an unweighted comparison of monthly means, not a day-weighted annual average or a measure of daytime maximum temperatures. The largest monthly increase was in December, with a difference of +1.84 °C. By contrast, June had the largest monthly decrease, a difference of -0.85 °C; these month-specific differences do not imply that every month changed in the same direction.

Changes in rainfall

Averaged across calendar months, mean daily rainfall had a difference of +0.25 mm/day in the more recent period. This is an unweighted mean of monthly daily-rainfall averages, not an annual total or a day-weighted average. The largest monthly increase occurred in October, with a difference of +1.39 mm/day; the largest decrease was in February, at a difference of -0.58 mm/day. These are differences in mean daily amounts for the named months, not changes in monthly rainfall totals.

Changes in sunshine duration

Averaged across calendar months, mean daily sunshine duration had a difference of -0.42 hours/day compared with the earlier reference period. This summarizes monthly means rather than describing every month or the total sunshine accumulated over a year. The largest monthly decrease was in June, with a difference of -0.93 hours/day. In February, the largest increase was a difference of +0.03 hours/day; the contrast between these months shows why the across-month mean should not be read as an identical change throughout the year.

Changes in snowfall

For mean daily snowfall, the unweighted average across calendar-month means was unchanged at the displayed precision, with a difference of 0.00 mm/day. This rounded comparison does not establish that snowfall was absent or that values were identical beyond the displayed precision.