Most guides give January one verdict. It needs two, because the first week and the last three weeks are barely the same month.
Everything that makes Hawaii expensive in late December is still true on January 2. Almost none of it is still true on January 12.
The two Januarys
Through about January 7 you are still inside the holiday period. Rates are at or near their annual peak, flights are full, rental cars are scarce and the popular beaches and trails are as busy as they get all year. If these are the only dates you have, it is a fine trip, but book early and expect to pay December money.
From roughly January 8 it changes quickly. Mainland schools go back, the holiday traffic leaves, and rates fall to some of the lowest of the winter. The weather has not changed. The whales have not left. You are simply there after everyone else went home.
That second window is the genuinely useful thing about January, and it is the part most month-by-month guides skip. Martin Luther King weekend puts a small bump in the middle of it, nothing like Presidents Day in February.
The whales are already here
Humpbacks arrive through December and the population builds through the winter. January is not quite the peak that February is, but the difference matters far less than people assume. There are plenty of whales in January, and there are fewer boats sharing them.
The Auʻau Channel between Maui, Lānaʻi and Molokaʻi is shallow and sheltered and holds the highest concentration in the islands. You do not need to pay anybody: whales are regularly visible from Maui's west and south shorelines, and twenty patient minutes with binoculars usually does it.
A boat adds a hydrophone, which is the part people remember. Federal rules keep vessels 100 yards off, and an operator worth booking tells you that instead of promising a close encounter.
The surf is the biggest of the year
North Pacific swell peaks in January. On Oʻahu's north shore, Maui's north coast and Kauaʻi's north end, that means waves that are extraordinary to watch and genuinely dangerous to enter. People drown in Hawaii every winter doing what looked fine from the sand.
The practical version is simple. In January, swim and snorkel on south and west coasts, and treat north shores as somewhere you go to look. That is not a restriction so much as a description of where the resort areas already are.
If a swell is large enough, the Eddie Aikau at Waimea Bay may run on a few days' notice. It is a real event rather than a scheduled one, and most years it does not happen at all.
Rain, and why it matters less than it sounds
January sits in the wet season and is among the wetter months. What that means in practice is decided almost entirely by which coast you sleep on.
Hawaii's mountains split every island into a wet windward side and a dry leeward side, and the difference is not subtle. Hilo can take ten times the rain of Kona in the same month. Base yourself leeward, on Wailea, Kīhei, Kāʻanapali, Waikīkī, Poʻipū or Kona, and most days are dry with passing showers.
The rain also buys you something. January is when the waterfalls run hardest and the valleys are at their greenest. Wailua, Waimea Canyon and the windward cliffs look in January the way they look in photographs, and in September they often do not.
Where to base yourself
Leeward, for the reason above, and it is worth being deliberate about it in January in a way that matters less in summer.
On Maui that means the south shore or the west side, and the choice between them is the real accommodation decision. On Oʻahu, Waikīkī and the leeward coast. On Kauaʻi, Poʻipū on the south shore rather than Hanalei, which is beautiful and takes serious winter rain. On Hawaiʻi Island, Kona over Hilo unless the volcano is the point of the trip.
You will want a car. Mid-January is the easy time to get one, but the first week is not, and that is the week people wait too long on.
What to pack for January
Start from the packing list and add:
- A light rain shell. Not a heavy coat. Showers pass quickly and it is still warm underneath.
- A rash guard, if cooler water bothers you. January averages 77 Fahrenheit, a degree off February's annual low rather than the bottom itself.
- A warm layer for boats and early starts. A whale watch at 7am in January is windy and colder on the water than the forecast suggests.
- Binoculars. The one January-specific item worth the space, and they work from the beach.
Compact 8x42 binoculars for whale watching
Is January a good month?
The second half of it is one of the best-value trips in the Hawaiian year, and it is underrated mostly because the first week gives the whole month a reputation for being expensive. Whales, waterfalls at full strength, green mountains, thin crowds and winter rates that are nowhere near the December ones.
The first week is the opposite: peak price, peak crowd, same weather. Worth it only if those are the dates you have.
If you can move a week either way, move later, not earlier. And if your dates are genuinely open, the full month-by-month comparison is the place to start, or September if warm calm water matters more to you than humpbacks.
Check the live numbers
Every month, side by side, is on the Hawaii weather reference: monthly rainfall for five stations plus sea temperature, taken from NOAA. The figures on this page describe a typical year. For the one you are actually travelling in:
- Water temperature, NOAA station 1612340. Live and historic readings from Honolulu Harbor. The monthly averages quoted here are the 34,802 hourly observations, 2021 to 2024 mean from this station.
- National Weather Service, Honolulu. Forecasts and warnings for every island, including the high surf advisories that decide which coasts are swimmable this week.
- National Hurricane Center. Worth a look in the week before you fly between June and November, and worth ignoring the rest of the year.
