Climate Change Chart of Penang Island, Malaysia

Overview of climate changes

Temperature changes

Averaged across calendar months, monthly mean temperature shows a difference of +1.07 °C compared with the earlier reference period. This is an unweighted mean of the monthly means, not a day-weighted annual average, and it describes the aggregate rather than every month; these temperatures are not daytime maximums. The largest monthly increase was in March, with a difference of +1.28 °C. That marks the strongest increase among the supplied monthly temperature differences, not a continuous trend between the reference periods.

Changes in rainfall

Averaged across calendar months, mean daily rainfall has a difference of +3.11 mm/day compared with the earlier reference period. This is an unweighted mean across monthly means, not a day-weighted annual average; it describes daily rainfall averaged by month, not monthly rainfall totals, and does not mean every month became wetter. The largest monthly increase was in November, where mean daily rainfall had a difference of +6.84 mm/day. By contrast, March had the largest monthly decrease, a difference of -0.01 mm/day. These identify the largest increases and decreases among the supplied monthly differences, rather than changes in monthly totals.

Changes in sunshine duration

Averaged across calendar months, mean daily sunshine duration shows a difference of -0.73 hours/day compared with the earlier reference period. This unweighted average of monthly means summarizes the overall comparison; it is not a day-weighted annual figure and does not imply the same change in every month. The monthly pattern was uneven: March had the largest increase, with a difference of +0.09 hours/day, while November had the largest decrease, with a difference of -1.45 hours/day. These are differences in mean daily sunshine hours for those months, not statements about every day.