WEATHER · CLIMATE NORMALS · 1991–2020
Port Moresby Climate — Averages by Month
What the weather in Port Moresby, PGaverages across a standard 30-year period. Each month's figure is the 1991–2020 mean temperature and total rainfall from the ERA5 reanalysis — the long-run normal a place settles around, not a forecast for any particular day.
Month-by-month normals
| Month | Avg temperature | Avg rainfall |
|---|---|---|
| January | 26.7 °C | 236.8 mm |
| February | 26.6 °C | 205.6 mm |
| March | 26.2 °C | 284.8 mm · wettest |
| April | 26.2 °C | 184.4 mm |
| May | 25.9 °C | 89.9 mm |
| June | 25.4 °C | 56.6 mm |
| July | 24.8 °C | 35.0 mm |
| August | 24.7 °C · coldest | 40.1 mm |
| September | 25.3 °C | 49.9 mm |
| October | 26.0 °C | 68.8 mm |
| November | 26.6 °C | 118.8 mm |
| December | 26.8 °C · warmest | 180.9 mm |
How to read these numbers
These are reanalysis normals, not readings from a single weather station. They come from the ERA5 0.25° (~25 km) global reanalysis grid, sampled at the grid cell nearest Port Moresby — centred at 9.50°S, 147.25°E. A reanalysis blends observations with a physics model onto an even grid, so a coastal or mountain city's cell can read a little cooler, warmer, wetter or drier than the city centre itself. The month-to-month shape — when it's hot, when it rains — is what these normals capture best.
“Normal” means the 1991–2020 average, the current World Meteorological Organization standard period. A normal is what a place tends toward over decades — any single day, month or year can and will depart from it.