Weather in Honolulu in January

Prime time. If you get to pick your dates, January is the one. Highs average 25 °C, lows 22.2 °C, and rain falls on 11 days — nothing in the month is working against you.

Honolulu barely has seasons. January scores 80 out of 100 against a best of 81 in May — a gap small enough that the month you choose matters far less here than the week you choose.

Rain on 11 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

Averages flatten a month, and this one hides a few things: it never really gets hot: not one day in an average January reaches 30 °C; the day barely swings — 2.7 °C between the overnight low and the afternoon high. Across the twenty years measured, the hottest January day reached 26.9 °C and the coldest night fell to 19.3 °C, and the wettest single day dropped 87 mm — roughly 123% of the month's rain in one day.

January is moderately variable: 6 mm in the driest year against 208 mm in the wettest, around an average of 71 mm. Roughly two Januarys in three land near that average, and the third does something else entirely.

Wind sits around 16.9 km/h — a steady breeze rather than a nuisance, and welcome on the warmer days, and humidity runs at 75%, high enough to notice on the warm days without dominating them.

How January sits in the year

Temperatures hold steady either side: 25.6 °C in December, 25 here, 24.6 in February. Nothing about the timing within the month matters much. Rain has already shifted: 5 days fewer than December had.

Daylight in January

January sits at the dark end of Honolulu's year — 11 hours of daylight against 13.4 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

Sea temperature

The sea sits at about 24.1 °C in January — warm enough to stay in as long as you like. The sea peaks at 26.6 °C in September and bottoms out at 23.7 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

How busy it gets

Peak season. Expect the highest prices of the year and to be booking well ahead. If the dates are flexible, February is the trade worth considering — 5 points weaker on weather, and materially quieter.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

January in Honolulu versus nearby

Honolulu has no close neighbour worth comparing against, so the useful question is how January there compares with January elsewhere. San Francisco in January is a different proposition entirely — 11.1 °C cooler, and the harder one overall — 13.9 °C and rain on 9 days, against 25 °C and 11 here. San Jose in January is a different proposition entirely — 9.6 °C cooler, and the harder one overall — 15.4 °C and rain on 8 days, against 25 °C and 11 here.

So: January is effectively as good as it gets here — 1 points behind May, which is inside the margin where the weather stops being the deciding factor and price starts being it.

Every month in Honolulu

See all twelve months in Honolulu, or where else to go in January.