Climate Change Chart of Mexico City, Mexico

Overview of climate changes

Temperature changes

Monthly mean temperature was higher by a difference of +1.40 °C averaged across calendar months in the more recent period; this is an unweighted average of monthly means, not a day-weighted annual temperature or a measure of daytime highs. The strongest monthly increase was in February, with a difference of +2.12 °C. That identifies the largest increase among the monthly means, rather than describing every month or a continuous change between the reference periods.

Changes in rainfall

Mean daily rainfall showed an increase of +1.23 mm/day averaged across calendar months, an unweighted comparison of monthly means rather than a day-weighted annual average or monthly rainfall totals. The largest monthly increase occurred in September, with a difference of +3.75 mm/day in mean daily rainfall. By contrast, January had the largest monthly decrease, a difference of -0.26 mm/day. These contrasting monthly differences show why the overall mean should not be read as a description of rainfall in every month or of individual daily conditions.

Changes in sunshine duration

Mean daily sunshine duration had a difference of -0.10 hours/day averaged across calendar months, an unweighted average of monthly means rather than a day-weighted annual figure. The monthly pattern was not uniform: January recorded the largest increase, with a difference of +0.29 hours/day, while June recorded the largest decrease, with a difference of -0.38 hours/day. These are differences in average daily sunshine, not a measure of every day's conditions, and the aggregate mean does not imply that each month changed in the same direction.