Climate Change Chart of Amsterdam, Netherlands

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.46 °C compared with the earlier reference period; this is an unweighted mean of the month-by-month averages, not a day-weighted annual average or a continuous trend. The largest monthly increase was in January, with a difference of +4.00 °C. By contrast, April had the largest monthly decrease, a difference of -0.10 °C. These are changes in monthly mean temperature, not daytime maximum temperatures.

Changes in rainfall

Mean daily rainfall averaged across calendar months shows a difference of +0.61 mm/day compared with the earlier reference period. This unweighted mean summarizes the monthly averages; it is not a day-weighted annual figure, and the daily amounts should not be read as monthly totals. The largest monthly increase occurred in October, with a difference of +1.56 mm/day. That identifies the strongest month-specific increase among the supplied rainfall differences, rather than describing every month.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months had a difference of -0.08 hours/day in the more recent period. This is an unweighted average of calendar-month means, not a day-weighted annual measure or evidence of a continuous trend. The largest monthly increase was in April, with a difference of +0.42 hours/day, while June had the largest monthly decrease, a difference of -0.71 hours/day. These month-specific contrasts show why the overall mean difference should not be taken to mean that sunshine changed in the same direction in every month.

Changes in snowfall

Mean daily snowfall averaged across calendar months shows a difference of -0.09 mm/day compared with the earlier reference period. This is an unweighted summary of monthly means, not a day-weighted annual average, and the supplied differences indicate recorded snowfall in at least one reference period. The largest monthly decrease was in January, with a difference of -1.13 mm/day; in December, the largest monthly increase was a difference of +0.32 mm/day. The overall decrease therefore does not describe the direction of change in every month.