Will it be miserably hot in September?

Question

Recently came across a few posts where many were saying how hot and humid September is. Well, we’re booked for late September for 2 weeks (splitting our stay) so now I’m a little worried.

I have been to Kauai a few times, including in July (and early October), and don’t recall it was too bad, especially North. Is September that much worse? I have booked all places with A/c but would like to be able to leave the condo (haha). We could still cancel at this point but I’m afraid it might disappoint my travel companions (son and MIL). But are we going to be miserable?

Answer

Visiting Kauai in September is generally very similar to August and early October in terms of weather. You can expect warm temperatures, typically ranging from the low 70s°F at night to mid-80s°F during the day along the coast, with slightly cooler temperatures in higher elevation areas like Waimea Canyon or the North Shore mountains. Humidity is present, but it is often mitigated by trade winds, especially near the coast.

While some travelers describe September as hot and humid, it’s usually manageable, particularly if you’re staying in air-conditioned accommodations and planning your outdoor activities for mornings or late afternoons. The interior and southern parts of the island (Poipu, Koloa) tend to be warmer and sunnier, while the North Shore (Hanalei, Princeville) is generally breezier and slightly cooler.

Some tips to avoid discomfort:

Plan hikes and outdoor activities for early morning or later afternoon to avoid the peak sun hours.
Use light, breathable clothing and stay hydrated.
Seek shade during beach or sightseeing breaks, and enjoy indoor activities mid-day if it feels too hot.
Check if your accommodations have a lanai or outdoor fan to catch trade winds when you step outside.

Rain is less frequent in September than in the winter months, but short showers can occur, especially on the North Shore. Overall, most travelers find the heat manageable and not “miserably hot,” especially if you pace your activities and take advantage of breezes and shaded areas.

In summary, you’re unlikely to be miserable. With air-conditioned lodgings and some planning around peak heat hours, you can enjoy Kauai comfortably in late September. It’s very similar to your previous visits in July or early October, so your travel companions should be able to enjoy the trip without major discomfort.