Best island(s) to visit from Auckland in December/January weather?

Hello everyone, and first off, thanks for any help you can give. I'm in Auckland at the moment and am keen to explore one of the pacific islands during my summer holidays. I'd be looking to go to ones that are reasonably accessible from Auckland. From my understanding, places like French Polynesia and the Cook Islands will be in their wet season during Dec/Jan though, and I'd kind of like to avoid being rained on during my whole trip. Are there any islands in the Pacific that could have decent weather at this time of year? Or is the weather in the Cook Islands/ French Polynesia typically not that bad around Dec/Jan?
Thanks again for any insight you can give!

Weather in the Cook Islands over this timeframe is not bad. Last year we hardly had any rain, while it bucketed down in the western Pacific. If you seek accommodation on the NW side of Rarotonga, this is the more sheltered side of the island. While Aitutaki island to the north of Rarotonga receives less rain per annum, since it doesn't have the high mountains and cloud forest interest being part atoll and part volcanic.

Daily flights between Auckland and Rarotonga aboard Air NZ and Virgin Australia. You can select Aitutaki as your destination when booking with Air NZ. This international airline code-shares with Air Rarotonga, our domestic airline. 4 return flights per day from Raro to Aitutaki. The lagoon surrounding this island is extraordinarily beautiful and picturesque. Good accommodations options to fit all budgets, mostly on the beach-frontages.

I think you'll find generally similar weather throughout the South Pacific biome. That's just the way it is.

On average, the higher and larger islands will produce more rainfall. Conversely, smaller and lower islands will experience less precipitation.

On very large mountainous islands the lee side may have rainfall like that of a desert climate.