Warm
Average highs sit around 27°C, giving warm days by monthly-average standards.
September verdict
Atiu, Cook Islands in September
Weather score81Very good
Very good for holiday weather
Average highs sit around 27°C, giving warm days by monthly-average standards. Sunshine averages 0h per day, so this is not one of the brighter months. Rainfall averages 71mm, which is relatively low for holiday planning.
September weather
Monthly averages
Temp
27°C
Rain
71mm
Sun
0h
Sea
25°C
Weather score
81
Very good
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Drier
Rainfall averages 71mm, which is relatively low for holiday planning.
Limited sun
Sunshine averages 0h per day, so this is not one of the brighter months.
Swimmable
Sea temperatures average 25°C, which can work for swimming but may feel fresh.
Map
Weather map
Compare Atiu, Cook Islands with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
September27°C average high
September is on the cooler side of Atiu's year, useful if you prefer less intense daytime heat.
Warmest monthsJanuary to May and November to December
This stretch sets the upper range for average daytime heat.
Rain
September71mm average rain
September is one of Atiu's driest months, making outdoor days easier to plan than in wetter parts of the year.
Driest monthsJune to October
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
September0 hours average sun
September is close to Atiu's usual sunshine level, with limited seasonal swing across the year.
Brightest monthsAll year
Sunshine stays consistently strong through the year.
Sea temperature
September25°C average sea
September is one of the coolest sea months, so the water may feel fresher than in peak months.
Warmest seaJanuary to May and December
Sea temperatures are usually near 28°C in this stretch, so swimming comfort is at its strongest.
Weather score
September81 weather score
September is one of Atiu's best weather-score months, combining the strongest overall balance in the yearly averages.
Best weather monthsJune to November
These months have the strongest weather score in the monthly averages.