Climate and average weather in Port Moresby

In Port Moresby, the weather is muggy, hot, wet, and mostly cloudy and remarkably steady, with daytime highs holding near hot levels all year. The wettest stretch peaks around March.

Best: late May to late September

Over the course of the year, the temperature in Port Moresby typically varies from 23°C to 30°C, and is rarely below 21°C or above 31°C. December is the hottest month of the year, while July is the coldest.

Based on the travel score, the best time of year to visit Port Moresby for warm-weather activities is from late May to late September.

Hottest
Dec
30°
Coldest
Jul
23°
Wettest
Mar
276 mm
Driest
Jul
29 mm
Rain / yr
1459 mm
177 wet days
Daylight
11.4–12.6 h
shortest–longest
Elevation
25 m
9.5°S
Clearest
Aug
65% cloud

Port Moresby is capital of Papua New Guinea.

Density
1,182/km²
people per km²
Founded
1873

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Port Moresby weather by month, at a glance

The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.

Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around late May to late September.

Temperature through the year

Average highAverage lowShaded bands: 10–90% of days

Daily average highs and lows in Port Moresby, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.

Temperatures in Port Moresby stay fairly even through the year, without a distinct hot or cool season. The warmest month is December, with an average high of 30°C and low of 24°C; the coolest is July, with an average low of 23°C and high of 28°C.

Days typically run about 5°C warmer than nights year-round.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Avg high (°C)Avg low (°C)
Jan3024
Feb2924
Mar2924
Apr2924
May2924
Jun2823
Jul2823
Aug2823
Sep2823
Oct2924
Nov3024
Dec3024

How hot and cold Port Moresby really feels

Feels-like highFeels-like lowactual air temp

The felt-temperature range through the year — heat index on the day's high (summer humidity), wind chill on the night's low (winter wind). The dashed lines are the plain thermometer; the gap is how much hotter or colder it really feels.

On the hottest afternoons, once humidity is folded in, Port Moresby feels like about 34°C (around December 8). About 216 days a year carry some heat stress, peaking in December.

20°25°30°35°JanFebMarAprMayJunJulAugSepOctNovDec
Feels-like high (°C)Air high (°C)Feels-like low (°C)Air low (°C)
Jan34302424
Feb33292424
Mar33292424
Apr33292424
May32292424
Jun31282323
Jul30282323
Aug30282223
Sep31282323
Oct32292324
Nov33302424
Dec34302424

Average hourly temperature in Port Moresby

A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on December afternoons, near 30°C, and coldest before dawn in July, near 23°C.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM

Port Moresby weather by month

Every month at a glance. Click a month for its detailed page.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan30° / 24°22922.912.53.4
Feb29° / 24°19520.912.33.4
Mar29° / 24°27624.912.13.4
Apr29° / 24°17720.211.84.0
May29° / 24°8112.211.65.2
Jun28° / 23°518.611.56.2
Jul28° / 23°295.211.56.8
Aug28° / 23°346.411.76.8
Sep28° / 23°457.811.95.9
Oct29° / 24°621112.25.2
Nov30° / 24°11015.512.44.4
Dec30° / 24°17021.212.53.6

Chance of rain

How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.

Port Moresby gets about 1459 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.

The wetter season lasts 5.9 months, from around Nov 7 to May 4, peaking in March at about 83% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jul 17.

March is the wettest month by volume, with 276 mm over about 25 wet days; July is the driest, with 29 mm.

0%10%20%30%40%50%60%70%80%90%JanFebMarAprMayJunJulAugSepOctNovDecwetterdrierwettermostly drysome rainoften wetvery wetMar 12 · 83%Jul 17 · 17%
Rain on a day (%)Rain days
Jan7323
Feb7521
Mar8025
Apr6620
May4012
Jun279
Jul195
Aug206
Sep278
Oct3611
Nov5216
Dec6821

Monthly rainfall

Over a full year, Port Moresby collects about 1459 mm of rain across 177 wet days — roughly 122 mm in an average month.

It doesn’t fall evenly. March is the wettest month with 276 mm, while July is the driest at just 29 mm. The three wettest months alone bring about 48% of the year’s total.

050100150200250300JanFebMarAprMayJunJulAugSepOctNovDec229195276177815129344562110170
Rainfall (mm)Rain days
Jan22923
Feb19521
Mar27625
Apr17720
May8112
Jun519
Jul295
Aug346
Sep458
Oct6211
Nov11016
Dec17021

Clouds and sunshine

ClearMostly clearPartly cloudyMostly cloudyOvercast

How often the daytime sky is clear, partly cloudy or overcast.

In Port Moresby, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.

The clearer part of the year begins around May 10 and lasts for 6.7 months, ending around November 30. The clearest month is August, when the sky is clear, mostly clear, or partly cloudy 39% of the time on average.

The cloudier part of the year begins around December 1 and lasts for 5.3 months, ending around May 9. The cloudiest month is March, when it is overcast or mostly cloudy 93% of the time.

0%100%10%90%20%80%30%70%40%60%50%50%60%40%70%30%80%20%90%10%100%0%JanFebMarAprMayJunJulAugSepOctNovDecAug 10 · 42%Mar 9 · 4%mostly clearpartly cloudymostly cloudyovercastcloudierclearercloudier
Clearer (%)Cloudier (%)
Jan991
Feb892
Mar793
Apr1585
May2971
Jun3565
Jul3763
Aug3961
Sep3466
Oct3268
Nov2872
Dec1684

Daylight, sunrise and sunset

DaylightNight

Hours of daylight through the year, with sunrise and sunset times.

The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around December 16, brings about 12 h 36 min of light; the shortest, around June 17, only 11 h 24 min — a swing of roughly 1 h 12 min.

12 AM4 AM8 AM12 PM4 PM8 PM12 AMJanFebMarAprMayJunJulAugSepOctNovDec
Daylight (h)Sunrise (AM)Sunset (PM)
Jan12.56:066:36
Feb12.36:176:35
Mar12.16:196:23
Apr11.86:186:05
May11.66:215:55
Jun11.56:285:55
Jul11.56:326:02
Aug11.76:256:06
Sep11.96:076:04
Oct12.25:506:03
Nov12.45:436:10
Dec12.55:516:24

Sunny days

How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.

Port Moresby averages about 3 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 6 days.

The sunnier stretch runs 7.0 months, from around May 4 to Dec 1. The sunniest month is August, with roughly 6 sunny days (gloomy).

The greyest month is March, down near 1 sunny days — about 87% fewer than the August peak.

0510JanFebMarAprMayJunJulAugSepOctNovDecgreyersunniergreyergloomymixedAug 126 daysMar 90 days
Sunny daysSky
Jan1Gloomy
Feb1Gloomy
Mar1Gloomy
Apr2Gloomy
May4Gloomy
Jun5Gloomy
Jul5Gloomy
Aug6Gloomy
Sep5Gloomy
Oct5Gloomy
Nov4Gloomy
Dec2Gloomy

Humidity comfort

DryComfortableHumidMuggyOppressiveMiserable

Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.

Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.

Port Moresby is humid all year round — on a typical day the air feels at least humid, and there is no real dry season to wait for.

The stickiest month is January, when it feels muggy, oppressive or miserable about 100% of the time. Even in August, the mildest month, the air is dry or comfortable only 0% of the time.

0%10%20%30%40%50%60%70%80%90%100%JanFebMarAprMayJunJulAugSepOctNovDecmiserableoppressivemuggyhumid
Humid (%)Muggy (%)Oppressive (%)Miserable (%)
Jan037819
Feb047719
Mar047522
Apr056530
May086922
Jun219737
Jul534610
Aug1135540
Sep726662
Oct220717
Nov187120
Dec037126

Wind

Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.

This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.

Across the year, average wind speed in Port Moresby is typically calm, near 12 km/h, and varies moderately with the seasons.

The windier part of the year lasts 5.5 months, from around May 12 to Oct 24. The windiest month is July, averaging about 17 km/h (light breeze).

The calmer part of the year runs from around Oct 25 to May 11, with December the calmest month at about 8 km/h.

0510152025JanFebMarAprMayJunJulAugSepOctNovDeccalmerwindiercalmercalmlight breezebreezyJul 22 · 17 km/hDec 11 · 8 km/h
Wind speed (km/h)Feels
Jan9calm
Feb10calm
Mar9calm
Apr9calm
May12light breeze
Jun15light breeze
Jul17light breeze
Aug17light breeze
Sep15light breeze
Oct12light breeze
Nov9calm
Dec8calm

Hazard calendar for Port Moresby

In seasonPeak

When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.

Port Moresby sits in the South Indian Ocean cyclone belt; the season peaks January–March.

Port Moresby's monsoon runs December–April, when most of the year's rain falls.

Cyclone
Monsoon
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Best time to visit Port Moresby

TravelBeach/poolTemperatureCloudsPrecipitation

To characterize how pleasant the weather is in Port Moresby throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.

Around late September, Port Moresby is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.

Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.

The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit Port Moresby for general outdoor tourist activities is from late May to late September, with a peak score in the third week of July.

0246810JanFebMarAprMayJunJulAugSepOctNovDecbest timetravel scoretemperaturecloudsprecipitationJul 18 · 6.9

The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

Travel score (0–10)Rating
Jan3.4poor
Feb3.4poor
Mar3.4poor
Apr4.0fair
May5.2fair
Jun6.2good
Jul6.8good
Aug6.8good
Sep5.9good
Oct5.2fair
Nov4.4fair
Dec3.7fair

The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit Port Moresby for hot-weather activities is from early May to mid November, with a peak score in the third week of August.

024681012JanFebMarAprMayJunJulAugSepOctNovDecbest timebeach/pool scoretemperaturecloudsprecipitationAug 19 · 7.3

The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).

What to pack for Port Moresby, by month

EssentialRecommendedOptional

Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.

Port Moresby packs about the same all year — highs hold near 30°C. Across the year the things worth having are light clothes, rain gear and sun protection.

Light clothing
Warm layer
Winter coat
Rain gear
Sun protection
Windbreaker

In December, Port Moresby sees daytime highs around 30°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 21 days see rain.

Sea temperature near Port Moresby

Average ocean temperature at the nearest coast, month by month, banded into swim-comfort zones — the other half of the beach question.

The sea at the nearest coast (about 17 km away) is warmest in January at about 29°C and coldest in August near 25°C.

The water stays above 20°C all year — warm enough for a swim any month.

24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb29Tropical
Mar29Tropical
Apr29Tropical
May28Warm
Jun27Warm
Jul26Warm
Aug25Warm
Sep25Warm
Oct26Warm
Nov27Warm
Dec29Tropical

UV index (midday) in Port Moresby by month

LowModerateHighVery highExtreme

Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.

Under clear skies, the midday UV index in Port Moresby peaks around March 10 at about 16 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 20 at about 9 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highExtremeMar 10UV 16Jun 20UV 9
UV index (midday)Level
Jan15Extreme
Feb16Extreme
Mar16Extreme
Apr14Extreme
May11Extreme
Jun9Very high
Jul10Very high
Aug12Extreme
Sep14Extreme
Oct14Extreme
Nov13Extreme
Dec14Extreme

Average hourly UV index in Port Moresby

LowModerateHighVery highExtreme

Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.

The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.

UV falls off far faster than brightness as the sun drops, so even in March the burn window is concentrated in the middle of the day: about 8.5 hours a day reach index 3 (protection recommended), and 7 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.

JanFebMarAprMayJunJulAugSepOctNovDec12 AM2 AM4 AM6 AM8 AM10 AM12 PM2 PM4 PM6 PM8 PM10 PM12 AM
UV ≥ 3 (h/day)UV ≥ 6 (h/day)
Jan8.57
Feb8.57
Mar8.57
Apr86
May7.55
Jun74.5
Jul75
Aug86
Sep86.5
Oct8.56.5
Nov8.56.5
Dec8.56.5
Almanac & agriculture

Growing season

Chance of a frost-free dayFrost-free year round

Port Moresby is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.

0%25%50%75%100%JanFebMarAprMayJunJulAugSepOctNovDecfrost-free year round
Frost-free chance (%)Frost nights
Jan1000
Feb1000
Mar1000
Apr1000
May1000
Jun1000
Jul1000
Aug1000
Sep1000
Oct1000
Nov1000
Dec1000

Growing degree days

Degree days (base 10°C)Frost-free shaded

Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. Port Moresby banks about 5,906 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around December.

02,0004,0006,000JanFebMarAprMayJunJulAugSepOctNovDec
Growing degree days (°C·days)
Jan527
Feb472
Mar512
Apr492
May500
Jun468
Jul468
Aug467
Sep468
Oct503
Nov503
Dec528

Solar energy

Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.

Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.

Port Moresby receives about 5.1 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.2 and 6.0 kWh/m².

The brighter stretch of the year lasts 5.9 months, from around Aug 29 to Feb 24. The brightest month is October, averaging about 5.9 kWh/m² (bright).

The dimmest month is June, down near 4.3 kWh/m² — roughly 27% less than the October peak.

01234567JanFebMarAprMayJunJulAugSepOctNovDecbrighterdimmerbrighterdimmoderatebrightintenseOct 246.0 kWhJun 264.2 kWh
Solar energy (kWh/m²)Level
Jan5.5Bright
Feb5.2Bright
Mar4.9Bright
Apr4.8Bright
May4.6Bright
Jun4.3Bright
Jul4.4Bright
Aug4.9Bright
Sep5.5Bright
Oct5.9Bright
Nov5.9Bright
Dec5.6Bright

Where is Port Moresby?

Port Moresby sits at 9.5°S, 147.2°E, 25 m above sea level, in Papua New Guinea. The nearest listed city is Popondetta, 143 km away.

PopondettaBuloloLaeGorokaDaruMadangMount HagenMendi

What Port Moresby looks like

Topography around Port Moresby

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Port Moresby.

Within 3 km, the terrain around Port Moresby has only modest variations in elevation — a maximum elevation change of 229 m around an average of 21 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 402 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,978 m.

The land around Port Moresby is covered by water (69%) within 3 km, water (53%) and grassland (24%) within 16 km, and trees (55%) and water (37%) within 80 km.

3 km
229 m
16 km
402 m
80 km
3,978 m
treesgrasslandartificial surfacesbare terrainwatermangroves
Nearby: Popondetta 143 km · Bulolo 259 km · Lae 307 km · Goroka 424 km · Daru 435 km · Madang 497 km · Mount Hagen 515 km · Mendi 534 km

Papua New Guinea travel facts

Travel advisory
Level 3
Reconsider Travel
Power plugs
Type I
240 V · 50 Hz
Prices
≈ 58% of US
price level, 2025
GDP per capita
$3,020
2025
Homicide rate
9.3
per 100k, 2010
Road deaths
12.6
per 100k/yr, 2019
Income group
Lower middle
World Bank
Religion
Protestant 64%Roman Catholic 26%other Christian 5%non-Christian 1%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Port Moresby (-9.4772°, 147.1509°, elevation 25 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).