Climate Change Chart of Porto Alegre, Brazil

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +0.31 °C; this is an unweighted comparison of monthly means, not a day-weighted annual average or a measure of daytime highs. The monthly pattern was not uniform: the largest increase was in January, at a difference of +1.25 °C, while the largest decrease was in May, at a difference of -0.55 °C. These month-specific differences describe averages for those calendar months, rather than a continuous change between the reference periods.

Changes in rainfall

Mean daily rainfall averaged across calendar months had a difference of +0.49 mm/day, an unweighted mean of monthly differences rather than a day-weighted annual average or a monthly rainfall total. The shifts varied by month: September had the largest increase, a difference of +1.91 mm/day, while January had the largest decrease, a difference of -1.66 mm/day. These daily-mean comparisons show that the aggregate difference did not apply uniformly across calendar months; they do not describe rainfall on every individual day.

Changes in sunshine duration

Mean daily sunshine duration, expressed as hours per day, had an unweighted difference of -0.17 hours/day when averaged across calendar months; this is not a day-weighted annual average. Month-specific differences went in both directions: February recorded the largest increase, at +0.46 hours/day, whereas March recorded the largest decrease, at -0.67 hours/day. The overall mean therefore summarizes differences among monthly averages and should not be read as a change applying to each month or each day.