Port Moresby weather in September

In September, Port Moresby sees average daytime highs of 28°C and overnight lows near 23°C, with 45 mm of rain across 7.8 wet days and about 11.9 hours of daylight. It is the 9th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 17% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 11 h 48 min at the start of September to 12 h 06 min by month's end. Set against the rest of the year, September is Port Moresby's 3rd-clearest and 3rd-windiest month. For the whole year in context, see Port Moresby's year-round climate.

Daytime high
28°
9th warmest
Overnight low
23°
3rd coldest
Rainfall
45 mm
7.8 wet days
Daylight
11 h 54 min
6:07 AM – 6:04 PM
Cloud cover
68%
3rd clearest
Wind
15 km/h
3rd windiest
Solar energy
5.45 kWh/m²
Travel score
5.9
out of 10

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.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 28°C through the month.

A typical September day in Port Moresby reaches about 28°C in the afternoon and slips back to 23°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 27°C and 30°C. Set against its neighbours, September runs on par with August and on par with October.

20°23°25°28°30°151015202530
Avg high (°C)Avg low (°C)
12823
22823
32823
42823
52823
62823
72823
82823
92823
102823
112823
122823
132823
142823
152823
162823
172823
182823
192823
202823
212823
222823
232823
242823
252823
262923
272923
282923
292923
302923

How September really feels in Port Moresby

Once humidity and wind are folded in, September averages 0 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C
0
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Port Moresby weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 10th-wettest month here — the current month is highlighted below.

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

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 17% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 66%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
13664
23664
33664
43664
53664
63763
73763
83763
93763
103763
113763
123763
133664
143565
153565
163565
173466
183367
193268
203268
213169
223169
233169
243070
253070
263070
273070
283070
293070
303070

Chance of precipitation in September

Any precipitation

Port Moresby gets around 45 mm of rain over 7.8 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 27% and peaks near 32% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
124
224
324
424
524
624
723
823
923
1023
1123
1224
1324
1425
1525
1626
1727
1827
1928
2028
2129
2229
2330
2430
2530
2631
2731
2831
2931
3032

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the oppressive band about 66% of days. Sticky, muggy-or-worse air turns up on roughly 93% of them.

0%25%50%75%100%151015202530
Comfortable (%)Humid (%)Muggy (%)Oppressive (%)Miserable (%)
11929610
21928620
30928621
401028611
501028611
601028611
701028611
801028611
901028611
1001028611
110928621
120928621
130927631
140827641
150826651
160726661
170625681
180625681
190524701
200524692
210424702
220423712
230323722
240323722
250323722
260323713
270323713
280223723
290223723
300223714

Wind in September

Winds average 15 km/h in September.

Across September, daily wind ranges from about 14 km/h on the calmest days to 16 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
116light breeze
216light breeze
316light breeze
416light breeze
516light breeze
616light breeze
716light breeze
816light breeze
916light breeze
1016light breeze
1116light breeze
1216light breeze
1316light breeze
1416light breeze
1515light breeze
1615light breeze
1715light breeze
1815light breeze
1915light breeze
2015light breeze
2115light breeze
2215light breeze
2315light breeze
2415light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 48 min at the start of September to 12 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 18 minutes over September. Sunrise moves from 6:17 AM to 5:58 AM, and sunset from 6:06 PM to 6:03 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.86:176:06
211.86:166:06
311.86:156:05
411.86:156:05
511.96:146:05
611.96:146:05
711.96:136:05
811.96:126:05
911.96:126:05
1011.96:116:05
1111.96:106:05
1211.96:106:05
1311.96:096:04
1411.96:096:04
1511.96:086:04
1611.96:076:04
1712.06:076:04
1812.06:066:04
1912.06:056:04
2012.06:056:04
2112.06:046:04
2212.06:036:04
2312.06:036:03
2412.06:026:03
2512.06:026:03
2612.06:016:03
2712.06:006:03
2812.16:006:03
2912.15:596:03
3012.15:586:03

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.45 kWh/m².

For context, solar energy here swings from a low near 4.29 kWh/m² to a high of 5.92 kWh/m² in November across the year — September's 5.45 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.2Bright
25.2Bright
35.2Bright
45.3Bright
55.3Bright
65.3Bright
75.3Bright
85.3Bright
95.4Bright
105.4Bright
115.4Bright
125.4Bright
135.4Bright
145.4Bright
155.4Bright
165.4Bright
175.4Bright
185.5Bright
195.5Bright
205.5Bright
215.5Bright
225.5Bright
235.5Bright
245.5Bright
255.5Bright
265.6Bright
275.6Bright
285.6Bright
295.6Bright
305.6Bright
Planning a trip in September

Hazard calendar for Port Moresby

In seasonPeak

None of Port Moresby's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

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

Is September a good time to visit Port Moresby?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.9
Sightseeing
4th-best month of the year
6.9
Beach & pool
3rd-best month of the year

September is a reasonable time to visit Port Moresby for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Port Moresby in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Port Moresby sees daytime highs around 28°C and nights near 23°C. Pack light clothes. Worth having: sun protection. About 8 days see rain.

light clothessun protection

Sea temperature near Port Moresby in September

The nearest coast averages about 25°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

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 in Port Moresby in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 14 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

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
Location & terrain

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

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
September weather 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).