カウアイ島の月別の天気

Forum posters describe February as genuinely still winter here - warmer and sunnier than mainland winters, but with real odds of a rainy stretch, especially on the north shore, where winter swells can make many beaches unswimmable or force closures. Posters consistently steer February visitors toward Poipu on the south shore for the better shot at sun. When rain does fall, posters describe it as typically scattered, quick-moving trade showers rather than sustained downpours - often not even worth leaving the beach for, since ducking under cover for a few minutes is usually enough to wait it out. Posters call February capable of swinging either way - a genuinely lovely stretch or a genuinely rainy one - with no reliable way to guarantee which in advance.

May is the shoulder here, from late April to Memorial Day: the winter rains are over, the surf is moderate, the summer heat and humidity have not arrived and the island is not yet full. Regulars say the north shore takes a little more rain than the rest, but as brief afternoon showers or passing ones late at night and early in the morning. Our 54.6mm across 17.2 precipitation days is exactly that - three millimetres a day, frequent and trivial. On temperature we differ: they give highs of 80 to 85F where our row reads 23.6C, low enough to suggest the figure is sampled above the coast, so trust theirs on the beach. The record: 19C nights, 12 hours of sun and a 25.6C sea.

Regulars call June the island's best all-round weather month, past the wetter spring and ahead of hurricane season, with any rain typically a brief passing shower rather than an all-day washout. Our row backs the warmth, 24.7C over 20.1C nights, with 54mm of rain across a real 16 days - regulars are specific that this figure varies sharply by coast, with Princeville among the driest spots on the island in June and Poipu on the drier south shore too, while Kapaa on the east side sees roughly double Poipu's total. The sea runs a warm 26.4C, still short of high summer's peak but comfortable for a full day in the water. Humidity is noted as building further into July and August, making June the more comfortable of the two. The record: 12.4 hours of sun, a 16 kph wind and AQI 26.

The July question on Kauai is which shore, and the forum answers it in inches: Princeville on the north averages about 5.8 of rain in July against Poipu's 1.0 on the south. The trades push cloud up over the mountains and empty it on the north side, which is also why the east and south get the sun and the cooling breeze. Our row tells the same story from the other end - 16.5 precipitation days carrying only 36.3mm, rain that lands often and amounts to almost nothing. In July most of it falls at night, and daytime trade showers last minutes, which is why residents do not plan around them. July is also neither the hottest nor the most humid month here. The record: 25.3C days that feel like 27C, 20.7C nights, 12.3 hours of sun, a 26.8C sea and a 17 kph trade wind.

Kauai's forum calls August and September the warmest months, hot by Hawaii standards, high 80s to low 90s°F with real humidity. Regulars note it's also a genuinely dry month overall — passing showers do occur, usually brief, 5-10 minutes — and flag August as the start of hurricane season, with the North Shore typically wetter than the south-facing Poipu side.

September is the hottest month in the islands and can be hot, muggy and stormy - though residents say that as long as the trade winds are running, a fan is enough. Our row's 25.9C over 21.1C reads as 28C at 76 percent humidity. The number that needs explaining is 14.2 precipitation days, which sounds like a wet fortnight until you see the 38.7mm spread across them: under three millimetres a day, which is exactly the brief showers regulars describe between sunny warm spells. For the driest ground they point west, with Poipu on the south shore the usual answer. This is also low season, and the honest caveat is hurricanes - the season runs June to November and September and October carry slightly more risk, so they suggest insurance. The record: 11.1 hours of sun, a 27.6C sea and AQI 22, the cleanest air in this collection.

Regulars are specific the south shore around Poipu reads as the warmest, driest option this month, winter rains not yet properly set in even though this technically counts as the wettest month of the year by the numbers - most of the real rain still arrives December through February. Our row backs that warm, genuinely wet read, 23.7C over 19.7C nights feeling 21C, with 44.6mm of rain across 14.4 days and humidity at 79 percent. Regulars are consistent many days logged as "rain" bring less than a tenth of an inch, hardly enough to notice, while the north shore can see huge swells building even on an otherwise calm week. The sea sits at a warm, swimmable 26.8C. The record: 10 hours of sun, a 15.9 kph wind and AQI 29.