デトロイト 9月の天気
デトロイトの9月:暖かい、雨が多い、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
デトロイトでは12か月中1位 · 9月に訪れたい旅行先で1413か所中217位 · 快適スコア90/100(Sランク)
- 日中
- 25°C
- 夜
- 16°C
- 雨の日
- 6
- 日照
- 9.5 h
- 湿度
- 73%
- 日の長さ
- 13 h

9月のデトロイトについての旅行者の声
The forum's September advice for Detroit is about timing within the month rather than the month itself: the first couple of weeks are usually very pleasant, while by the end of September you never know. Regulars point at the week straight after Labor Day as the sweet spot — schools go back at the end of August so the crowds have thinned, and the weather is still predictable. The averages hold that up: near 24°C by day, around 16 overnight.
デトロイトのほかの月
Regulars call this a genuinely good pick within the city's shoulder season, specifically for sports fans since baseball, hockey, basketball and football overlap here this time of year. Our row backs the cooling, changeable read, 17.8C over 8.8C nights feeling 6C, with 77.4mm of rain across 9.2 days and a real 22.6 kph wind. Regulars are consistent this month is genuinely variable enough that checking the forecast starting about a week out is worth doing, since a run of highs in the low 50s Fahrenheit with lows still above freezing can shift meaningfully within that window. The record: humidity 72 percent, 7.5 hours of sun and one of the cleanest air readings in this project, AQI 37.
Regulars call this a typically hot, humid summer month, low-to-mid 80s Fahrenheit by day and rarely much cooler, though occasionally pushing into the 90s - and specifically warn that a passing storm can drop the temperature by as much as 30 Fahrenheit degrees in half an hour, a swing worth packing a light jacket for even on an otherwise hot day. Our row backs the heat, 28.3C reading as a real 30C, over 19.2C nights, with 123.6mm of rain across 8.5 days - a real, humid-summer total rather than the occasional shower. Regulars pair the jacket advice with an umbrella, treating a sudden downpour as routine rather than exceptional for the season. The record: humidity 71 percent, 11.6 hours of sun, a 17.9 kph wind and AQI 52.
June opens the stretch regulars recommend here, June through September, and it is the month the city's outdoor half becomes usable - the riverwalk, Belle Isle, the market, a ballgame. Our row gives 27.1C reading as 28C over 16.8C nights at 67 percent humidity, which is warm without the August weight. Rain is 88.6mm across 7.7 days, so afternoon storms rather than drizzle, and a 20.5 kph wind keeps the riverfront fresher than the inland numbers suggest. Anyone continuing north should know the boards are clear that early June is still chilly past mid-Michigan. The record: a dew point of 13.4C, 12.1 hours of sun inside 15.2 of daylight, and AQI 66.
May in Detroit is the month regulars describe as either lovely or cool and rainy, with no way to know in advance - April and May are the two they call genuinely unpredictable in Michigan, and the advice that follows is to keep a plan that works indoors. One regular's figure of a mid-50s to 60F daily high reads low against our row's 21.8C average, and likely describes the start of the month rather than the end of it. What May reliably brings is baseball: the season is underway and a game at Comerica Park is the thing they suggest. It is also the wet end of spring here, 92.3mm across 10.7 days. The record: 11C nights that feel like 8C, a 21.5 kph wind and 10.3 hours of sun.
通年のメモはデトロイトの概要ページにあります。 地図のデトロイトのカードから自分のメモを追加できます。
デトロイトの気候平年値 — 9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。
9月のデトロイトの混雑
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。
ピークの混雑Detroit Jazz Festival、アメリカ合衆国のSummer break(推定)
ピークの混雑混雑ショルダーシーズン閑散
デトロイトの天気が良い月
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)。
天気が最高デトロイトの天気が最も良いのは5月、6月、9月です — ひと続きのシーズンではなく、別々の時期です。
9月にはDetroit Jazz Festivalがあります。
天気が最高天気はまずまず天気が厳しい
9月のデトロイトのイベント
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。
- 季節
Riverfront and Belle Isle season
6月1日〜9月15日 · 例年夏季営業スタートThe riverwalk, the Belle Isle beach and the pop-up bars along the Dequindre Cut only exist for one season, and Detroit uses all of it. Everything closes again by October. 出典 ↗
- 祭り
Detroit Jazz Festival
8月30日〜9月8日 · 例年音楽祭混雑Four free days over Labor Day weekend, centred on Hart Plaza, and the largest free jazz festival anywhere. No ticket, no fence, and the last warm weekend of the year. 出典 ↗
近くで開催中のイベント
デトロイトから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。
デトロイトはどこにある?
9月のデトロイト — よくある質問
- 9月はデトロイトを訪れるのに良い時期ですか?
- デトロイトの9月:暖かい、雨が多い、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、デトロイトの12か月中1位です(90/100)。
- 9月のデトロイトはどんな天気ですか?
- 9月のデトロイトは、平均最高気温24.6°C、最低気温15.6°C、降水量は約87.9 mmで、雨の日はおよそ6.4日です。
- 9月のデトロイトの大気質はどうですか?
- 9月のデトロイトの米国大気質指数(US AQI)は、平均約45です。
300 km圏内:ClevelandのCleveland National Air Show(9月5日〜7日)、ColumbusのAll American Quarter Horse Congress(9月26日〜10月24日)。