Port Moresby weather in December
In December, Port Moresby has daytime highs averaging 31 °C, nights around 24 °C, with 21 wet days, and a sea temperature of 29 °C. Figures are 1991–2020 climate normals.
- 30.7°C Average high
- 23.9°C Average low
- 21days Wet days
- 170mm Rainfall
- 28.9°C Sea temperature
- 13h Daylight
Daily temperatures through December
How December develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 December | 31.0 °C | 23.8 °C | 63 % |
| 11–20 December | 30.6 °C | 23.8 °C | 67 % |
| 21–31 December | 30.7 °C | 24.0 °C | 69 % |
- Rain is most likely over days 21–31 of December (69 % of days) and least likely over days 1–10 (63 %).
What to expect
| Measure | Typical December | Share of the month |
|---|---|---|
| Days above 25 °C | 31 of 31 | 100 % |
| Days above 30 °C | 22 of 31 | 70 % |
| Days below 0 °C | 0 of 31 | 0 % |
| Days with more than 1 mm rain | 21 of 31 | 67 % |
Conditions in December
| Measure | Average |
|---|---|
| Mean temperature | 27 °C |
| Record high (1991–2020) | 35 °C |
| Record low (1991–2020) | 18 °C |
| Relative humidity | 82 % |
| Wind speed | 13 km/h |
| Cloud cover | 81 % |
December compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 30.3 °C | 234 mm | 88 % |
| February | 30.1 °C | 201 mm | 89 % |
| October | 30.8 °C | 61 mm | 69 % |
| November | 31.0 °C | 106 mm | 73 % |
| December | 30.7 °C | 170 mm | 81 % |
See all twelve months for Port Moresby
- December is the 3rd warmest month here.
- It is the 8th driest month of the year.
- It ranks 8th for least cloud cover.
- Days last about 13 hours from sunrise to sunset.
- It rains on 21 of 31 days — 67 % of the month.
- Nights are about 6.9 °C cooler than the middle of the day.
- The hottest December day on record since 1991 reached 35 °C, 4.3 °C above the usual daytime high.
- Beach score: 65 / 100 — see how this is calculated.
QuestionsDecember in Port Moresby, answered
How warm is Port Moresby in December?
Daily highs average 31 °C and nights fall to about 24 °C, a spread of 6.9 °C between afternoon and dawn. That makes December the 2nd warmest month of the year here.
Does it rain much in Port Moresby in December?
December averages 170 mm of rain, spread over about 21 of the 31 days — 67 % of the month. Cloud cover averages 81 % of the sky.
Is the sea warm enough to swim in December?
The sea averages 29 °C off Port Moresby in December. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.
How long are the days in December?
Port Moresby averages 13 hours between sunrise and sunset in December. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
Data sources and method
- ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
- Open-Meteo — Open-Meteo.com. CC BY 4.0
- NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
- GeoNames — GeoNames.org. CC BY 4.0
- Normal period
- 1991–2020
- Dataset version
- era5-1991-2020-scores1.1
- Last processed
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. Full formulas are on the methodology page.
Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.