カウアイ島 8月の天気
カウアイ島の8月:暖かい、ときどき雨、空気がきれい — 一年で最も訪れやすい月のひとつ。
2026年9月更新 · ERA5再解析による気候平年値
カウアイ島では12か月中2位 · 8月に訪れたい旅行先で1413か所中72位 · 快適スコア93/100(Sランク)
- 日中
- 26°C
- 夜
- 21°C
- 雨の日
- 14
- 日照
- 11.7 h
- 湿度
- 76%
- 日の長さ
- 13 h

8月のカウアイ島についての旅行者の声
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.
カウアイ島のほかの月
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.
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.
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.
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.
地図のカウアイ島のカードから自分のメモを追加できます。
カウアイ島の気候平年値 — 8月
ERA5再解析による月平均値です。AQIはその月の平均US AQI(米国大気質指数)です。
8月のカウアイ島の混雑
その場所自体の混み具合 — 学校休暇や大型連休、編集部がタグ付けした月、そして天気の良さによる人気の高さ。快適スコアには含まれません。
混雑アメリカ合衆国のSummer break、主な訪問国のうち2か国で学校休暇(推定)
ピークの混雑混雑ショルダーシーズン閑散
カウアイ島の天気が良い月
この旅行先自身の一年間の快適スコアでランキングしています — 混み具合とは別のものです(上の「混雑」を参照)。
天気はまずまずカウアイ島の天気は一年を通じて大きく変わりません — どの月も快適さはほぼ一定です。
8月のカウアイ島のイベント
毎年の季節のイベント、自然の見どころ、休業、祝日 — 厳選し出典を明記しています。
- ルール
Haena State Park reservations
1月1日〜12月31日早めの予約をKee Beach and the Kalalau trailhead sit inside a capped park: entry, parking and the shuttle are all booked in advance and sell out a month ahead. Walking in past the gate is not an option. 出典 ↗
- 要注意
Central Pacific hurricane season
6月1日〜11月30日Hawaii is hit rarely, but Kauai is the island that gets hit: Iniki flattened it in 1992 and the north shore roads still close for days when a system passes near. August and September are the months. 出典 ↗
近くで開催中のイベント
カウアイ島から300 km以内 — 日帰りやちょっとした移動で行けて、今月何かがある場所です。快適スコアには含まれません。
カウアイ島はどこにある?
8月のカウアイ島 — よくある質問
- 8月はカウアイ島を訪れるのに良い時期ですか?
- カウアイ島の8月:暖かい、ときどき雨、空気がきれい — 一年で最も訪れやすい月のひとつ。SeasonMapの快適スコアでは、カウアイ島の12か月中2位です(93/100)。
- 8月のカウアイ島はどんな天気ですか?
- 8月のカウアイ島は、平均最高気温25.9°C、最低気温21.1°C、降水量は約37.4 mmで、雨の日はおよそ14.3日です。
- 8月のカウアイ島の大気質はどうですか?
- 8月のカウアイ島の米国大気質指数(US AQI)は、平均約23です。
300 km圏内:HonoluluのSouth shore surf season(4月15日〜9月30日ごろ)。