Cook Islands · Month comparison

September vs May

May ranks #1 overall vs September at #4. Dry season opens — the crowd-to-value sweet spot before New Zealand winter school holidays.

Cook Islands September — green palm tree on Rarotonga beach under clear dry-season sky

September

#4 of 12 months

Best match

Dry season continues — school holidays end, prices soften slightly, conditions remain excellent.

  • School holiday crowds thin after the first week — far easier to book Aitutaki day trips
  • Prices beginning to ease from July–August peak while weather remains exceptional
Cook Islands May — palm-fringed Rarotonga beach under clear dry-season skies

May

#1 of 12 months

Best match

Dry season opens — the crowd-to-value sweet spot before New Zealand winter school holidays.

  • 85mm of rain is genuinely manageable — most days are dry and clear
  • Prices still below the June–August premium before school holidays hit
FactorSeptemberMay
Weather score
9
8
Value score
6
7
Crowd score
6
7
Events score
5
5
Atmosphere
8
8
Avg high temp23°C24°C
Monthly rain70mm85mm
Daily sunshine7.5hrs7hrs

September trade-offs

  • Still 70mm of rainfall — occasional brief showers occur in the evenings
  • Some operators begin reduced scheduling ahead of the wet season return
  • Water still cool at 17°C low — not the warmest swimming conditions

May trade-offs

  • Evenings noticeably cooler than summer — pack a layer for open-air dinners
  • Some activities (lagoon cruises, sailing) operate reduced schedules before the main season
  • Less vibrant green in the interior as dry season bites
Scores compare months within Cook Islands. Climate data: Open Meteo ERA5 30-year normals (1991–2020). Methodology →