Climate Change Chart of Port Moresby, Papua New Guinea

Overview of climate changes

Changes in rainfall

Mean daily rainfall averaged across calendar months was lower in the more recent period, with a difference of -1.35 mm/day. This unweighted mean of monthly values is not a day-weighted annual average, and it does not imply a decrease in every month. The largest monthly decrease occurred in April, a difference of -4.80 mm/day, while January had the largest increase, at +1.20 mm/day. These figures describe mean daily rainfall, not monthly totals, and highlight that monthly differences varied in direction.

Temperature changes

Monthly mean temperature was higher on average across calendar months in the more recent period, with a mean difference of +0.79 °C. This is an unweighted comparison of monthly means, not a day-weighted annual average, and it does not mean that every month warmed by the same amount. The largest monthly increase was in December, at a difference of +1.33 °C; these are monthly mean temperatures, not daytime maximums.

Changes in sunshine duration

Mean daily sunshine duration averaged across calendar months increased in the more recent period, with a difference of +0.13 hours/day. This unweighted average of monthly means does not imply an increase in each month. The largest monthly increase was in December, at a difference of +0.46 hours/day, while the largest decrease was in September, at -0.49 hours/day. These monthly contrasts show why the modest overall mean difference should not be read as a uniform change through the year.