Cool
Average highs are around 12°C, so pack for cooler days.
September verdict
Stewart Island, New Zealand in September
Weather score18Poor
Poor for holiday weather
Average highs are around 12°C, so pack for cooler days. Sunshine averages 4h per day, so this is not one of the brighter months. Rainfall averages 98mm, so some wet days are possible.
September weather
Monthly averages
Temp
12°C
Rain
98mm
Sun
4h
Sea
11°C
Weather score
18
Poor
Seasonal climate calendar
TemperatureTemp
RainRain
SunSun
SwimSwim
Weather scoreWeather score
Trip feel
Showers
Rainfall averages 98mm, so some wet days are possible.
Limited sun
Sunshine averages 4h per day, so this is not one of the brighter months.
Cool sea
Sea temperatures average 11°C, so the water can feel cool.
Map
Weather map
Compare Stewart Island, New Zealand with nearby places by weather score, rain, sun, temperature, and swim conditions.
Temperature
September12°C average high
September is on the cooler side of Stewart Island's year, useful if you prefer less intense daytime heat.
Warmest monthsJanuary to March and December
This stretch sets the upper range for average daytime heat.
Rain
September98mm average rain
September sits near Stewart Island's yearly rainfall average, so rain is a normal planning factor rather than an outlier.
Driest monthsFebruary to March and June to December
This is the drier part of the year, when outdoor plans usually need less weather flexibility.
Sun
September4 hours average sun
September sits close to Stewart Island's yearly sunshine average, so it is a middle-of-the-pack month for bright days.
Brightest monthsJanuary to February and October to December
This stretch has the strongest sunshine in the monthly averages.
Sea temperature
September11°C average sea
September is one of the coolest sea months, so the water may feel fresher than in peak months.
Warmest seaJanuary to April and December
Sea temperatures are usually near 14°C in this stretch, so swimming comfort is at its strongest.
Weather score
September18 weather score
September scores below Stewart Island's yearly average, so the weather trade-offs are more noticeable.
Best weather monthsJanuary to March and November to December
These months have the strongest weather score in the monthly averages.