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Port Moresby weather by month: averages, rainfall & climate trends

Warmth in Port Moresby is remarkably steady: only 1.8°C separates the warmest month from the coolest, so there is no cold season to speak of. Rainfall leans toward the stretch from December to April. Port Moresby weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

−0.8°Chigh near average

29° / 25°Today
30° / 24°Average
see today in detail →

How it's changed

+1.6°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49189days above 30°C a year now (2016–2025) · 34 in the 1940sdays above 30°C · 34 in the 1940s+1.6°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 238 mmhigh 30°low 25°February, rain 241 mmhigh 30°low 25°March, rain 290 mmhigh 29°low 24°April, rain 198 mmhigh 29°low 24°May, rain 94 mmhigh 29°low 24°June, rain 59 mmhigh 28°low 24°July, rain 44 mmhigh 28°low 23°August, rain 41 mmhigh 28°low 23°September, rain 49 mmhigh 29°low 23°October, rain 74 mmhigh 30°low 24°November, rain 110 mmhigh 30°low 24°December, rain 187 mmhigh 30°low 25°wettest month March, 290 mm · 1,623 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Partly cloudy

Right now

25.9°

30°feels like
85%humidity
23°dew point
11 km/hfrom SE
UV index0.0
sunrise05:45sunset18:06day length12h 21m
TodayPartly cloudy29°25°
WedPartly cloudy29°25°
ThuMostly clear29°26°
FriMostly clear29°25°
SatMostly clear29°25°
SunMostly clear30°25°
MonMostly clear29°25°

On this date: October 20

Today (forecast)
29° / 25°
Average for October 20
30° / 24°

High near average · −0.8°C

  • Highest since 1940: 32.2° · 2001
  • Lowest since 1940: 20.2° · 1961
  • One year ago: 31° / 25°

Every October 20 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 20 on record (n = 87). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Port Moresby is sampled from the ECMWF ERA5 reanalysis at 9.48°S, 147.15°E, with daily records since 1940.

Coordinates
9.48°S, 147.15°E
Time zone
Pacific/Port Moresby
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

15 of the last 31 days were warmer than the historical average for that date. Average difference: 0.0°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

December brings the year's peak warmth, with afternoons typically reaching 29.9°C and nights around 24.6°C. At the other extreme, July brings afternoon highs of about 28.0°C and typical overnight lows of 23.1°C.

In total, Port Moresby averages about 1,623 mm of precipitation a year; March is usually the wettest month (290 mm) and August the driest (41 mm).

The record here starts in 1940, and since then the annual mean in Port Moresby has climbed 1.6°C from the first ten years to the last ten. The count of days past 30°C has risen from roughly 35 a year to 190 between the record's first and last decades.

Climate graph (climograph)

December is the warmest month, July the coolest: a yearly swing of 2°C. Wettest month: March (~290 mm). Whole year averages ~1,623 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Port Moresby month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainDaylightHighestLowest
January29.8°24.6°238 mm12.5 h34.2° (2013)21.8° (1966)
February29.6°24.6°241 mm12.3 h33.7° (2024)21.7° (1942)
March29.2°24.4°290 mm12.1 h33.4° (2023)19.2° (1966)
April29.1°24.3°198 mm11.8 h32.0° (2006)19.6° (1966)
May29.0°24.2°94 mm11.6 h32.0° (2022)18.9° (1953)
June28.4°23.6°59 mm11.5 h31.4° (2002)19.0° (1982)
July28.0°23.1°44 mm11.5 h31.7° (2010)18.5° (1940)
August28.3°23.1°41 mm11.7 h31.8° (2010)18.4° (2004)
September28.9°23.5°49 mm12.0 h32.1° (2010)18.3° (1961)
October29.5°23.9°74 mm12.2 h33.1° (2001)19.9° (1941)
November30.0°24.4°110 mm12.4 h33.6° (2021)19.8° (1946)
December29.9°24.6°187 mm12.6 h34.2° (2018)20.8° (1978)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +1.6°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.18°C per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Dec–Feb is warming fastest: +0.22°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 33.9 early in the record → 188.5 recently. Frost days: 0 → 0.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 2018, coldest in 1961: 34.2°C / 18.3°C.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~1,623 mm/year on average. Last decade: +7% vs that average. Long-term trend: −18 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Port Moresby

Which is the warmest month in Port Moresby?
On long-term average, the warmest month in Port Moresby is December (mean daily temperature of about 27.1°C) and the coolest is July (about 25.3°C).
How does today's temperature in Port Moresby compare to the historical average?
On October 20, 2026, Port Moresby is forecast to reach a high of 28.8°C and a low of 25.2°C. The long-term average for this date (the full record since 1940) is a high of 29.6°C and a low of 24.1°C, so today's high is 0.8°C cooler than that average.
How much has Port Moresby warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Port Moresby is about 1.6°C warmer.
How much does it rain in Port Moresby?
Port Moresby receives about 1,623 mm of precipitation per year on long-term average, with March typically the wettest month.
What is the average temperature in Port Moresby?
Over the full record (since 1940), the annual mean temperature in Port Moresby is about 26.3°C. The warmest month is December and the coolest is July.
What are the average temperatures in Port Moresby by month?
Average daily highs and lows for each month in Port Moresby (°C, full record since 1940): January 30°/25°, February 30°/25°, March 29°/24°, April 29°/24°, May 29°/24°, June 28°/24°, July 28°/23°, August 28°/23°, September 29°/23°, October 30°/24°, November 30°/24°, December 30°/25°.

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