Avarua weather in September

In September, Avarua sees average daytime highs of 23°C and overnight lows near 22°C, with 73 mm of rain across 8.4 wet days and about 11.9 hours of daylight. It is the 11th-warmest and 10th-wettest month of the year here.

Day-to-day highs hold fairly steady near 23°C through the month. The sky is clear or mostly clear about 29% of the time in September, and the air most often feels muggy.

Daylight stretches from about 11 h 36 min at the start of September to 12 h 12 min by month's end. Set against the rest of the year, September is Avarua's 3rd-clearest and 1st-windiest month. For the whole year in context, see Avarua's year-round climate.

Daytime high
23°
11th warmest
Overnight low
22°
2nd coldest
Rainfall
73 mm
8.4 wet days
Daylight
11 h 54 min
6:37 AM – 6:30 PM
Cloud cover
61%
3rd clearest
Wind
26 km/h
1st windiest
Solar energy
5.14 kWh/m²
Travel score
7.1
out of 10

Avarua is capital city of the Cook Islands.

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 23°C through the month.

A typical September day in Avarua reaches about 23°C in the afternoon and slips back to 22°C overnight — a 1°C spread between the day's warmth and the night's chill. On most days the high lands between 22°C and 25°C. Set against its neighbours, September runs on par with August and on par with October.

18°20°22°24°26°151015202530
Avg high (°C)Avg low (°C)
12322
22322
32322
42322
52322
62322
72322
82322
92322
102322
112322
122322
132322
142322
152322
162322
172322
182322
192322
202322
212322
222322
232322
242322
252322
262322
272322
282322
292322
302322

Avarua weather by month

How September compares with the rest of the year at a glance. September is the 11th-warmest and 10th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan26° / 25°21318.113.15.3
Feb27° / 25°1781712.75.1
Mar27° / 25°18618.612.15.3
Apr26° / 25°1531511.55.8
May25° / 24°12512.7116.3
Jun24° / 23°648.210.77.1
Jul23° / 22°989.210.87.1
Aug23° / 22°728.311.37.1
Sep23° / 22°738.411.97.1
Oct24° / 23°878.812.57.0
Nov25° / 24°10810.7136.6
Dec26° / 25°18914.513.35.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 29% 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 54%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14654
24753
34753
44753
54753
64753
74753
84753
94753
104753
114753
124852
134852
144852
154852
164753
174753
184753
194654
204753
214753
224654
234654
244654
254555
264555
274555
284456
294456
304456

Chance of precipitation in September

Any precipitation

Avarua gets around 73 mm of rain over 8.4 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 31% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
124
223
323
423
523
623
724
824
924
1025
1125
1225
1326
1427
1528
1628
1729
1830
1930
2031
2131
2231
2331
2431
2531
2631
2731
2831
2930
3030

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 36% of days. Sticky, muggy-or-worse air turns up on roughly 50% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1821273212
2821283212
3720283212
4720283212
5620293213
6620293313
7520293313
8519293313
9519293413
10419293413
11419293413
12419293513
13419293513
14319283614
15319283614
16318283714
17318273714
18318273715
19318273715
20318273815
21218273815
22218273815
23217273915
24217263915
25217264015
26217264015
27217264115
28216264115
29216264215
30216264214

Wind in September

Winds average 26 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 25 km/h on the calmest days to 26 km/h at its breeziest. It stays fairly steady from day to day.

0102030151015202530
Wind speed (km/h)Feels
125breezy
225breezy
325breezy
426breezy
526breezy
626breezy
726breezy
826breezy
926breezy
1026breezy
1126breezy
1226breezy
1326breezy
1426breezy
1526breezy
1626breezy
1725breezy
1825breezy
1925breezy
2025breezy
2125breezy
2225breezy
2325breezy
2425breezy
2525breezy
2625breezy
2725breezy
2825breezy
2925breezy
3025breezy

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 36 min at the start of September to 12 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 36 minutes over September. Sunrise moves from 6:52 AM to 6:23 AM, and sunset from 6:26 PM to 6:34 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.66:526:26
211.66:516:26
311.66:506:27
411.66:496:27
511.76:486:27
611.76:476:27
711.76:466:28
811.76:456:28
911.76:446:28
1011.86:436:28
1111.86:426:29
1211.86:416:29
1311.86:406:29
1411.86:396:29
1511.96:386:30
1611.96:376:30
1711.96:366:30
1811.96:356:30
1911.96:346:31
2012.06:336:31
2112.06:326:31
2212.06:316:31
2312.06:306:32
2412.06:296:32
2512.16:286:32
2612.16:276:32
2712.16:266:33
2812.16:256:33
2912.26:246:33
3012.26:236:34

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.14 kWh/m².

For context, solar energy here swings from a low near 3.44 kWh/m² to a high of 6.56 kWh/m² in December across the year — September's 5.14 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.7Bright
24.8Bright
34.8Bright
44.8Bright
54.8Bright
64.9Bright
74.9Bright
84.9Bright
95.0Bright
105.0Bright
115.0Bright
125.1Bright
135.1Bright
145.1Bright
155.2Bright
165.2Bright
175.2Bright
185.2Bright
195.3Bright
205.3Bright
215.3Bright
225.3Bright
235.3Bright
245.4Bright
255.4Bright
265.4Bright
275.4Bright
285.5Bright
295.5Bright
305.5Bright
Planning a trip in September

Is September a good time to visit Avarua?

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

7.1
Sightseeing
1st-best month of the year
5.6
Beach & pool
6th-best month of the year

September is one of the better times to visit Avarua for general sightseeing.

What to pack for Avarua in September

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

In September, Avarua sees daytime highs around 23°C and nights near 22°C. Worth packing: light clothes, rain gear, sun protection and a windbreaker. About 8 days see rain.

light clothesrain gearsun protectiona windbreaker

Sea temperature near Avarua in September

The nearest coast averages about 24°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 14 km away) is warmest in March at about 28°C and coldest in August near 24°C.

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

22°24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecrefreshingwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb28Warm
Mar28Warm
Apr27Warm
May26Warm
Jun25Warm
Jul25Warm
Aug24Warm
Sep24Warm
Oct25Warm
Nov26Warm
Dec27Warm

UV index in Avarua in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Avarua peaks around February 13 at about 16 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 10 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeFeb 13UV 16Jul 10UV 6
UV index (midday)Level
Jan15Extreme
Feb17Extreme
Mar13Extreme
Apr9Very high
May7Very high
Jun6High
Jul6High
Aug8Very high
Sep10Extreme
Oct12Extreme
Nov13Extreme
Dec13Extreme
Location & terrain

Where is Avarua?

Avarua sits at 21.2°S, 159.8°W, 7 m above sea level, in Cook Islands. The nearest listed city is Bora Bora, 994 km away.

Topography around Avarua

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

Within 3 km, the terrain around Avarua has significant variations in elevation — a maximum elevation change of 440 m around an average of 65 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 495 m; within 80 km, significant variations in elevation — a maximum elevation change of 478 m.

The land around Avarua is covered by trees (49%) and water (41%) within 3 km, water (92%) within 16 km, and water (98%) within 80 km.

3 km
440 m
16 km
495 m
80 km
478 m
treesgrasslandartificial surfaceswater
September weather nearby: Bora Bora 994 km · Alofi 1,086 km · Moorea 1,120 km · Punaauia 1,138 km · Faaa 1,141 km · Papeete 1,146 km · Pago Pago 1,389 km · Apia 1,512 km

Cook Islands travel facts

Power plugs
Type I
240 V · 50 Hz
Religion
Protestant 55%Roman Catholic 17%none/unspecified 16%other 5%

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 Avarua (-21.2075°, -159.7755°, elevation 7 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. 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).