フェニックス 9月の天気
フェニックスの9月:猛暑、雨が少ない、空気がきれい — おすすめできない時期(午後38°Cの暑さ)。
2026年9月更新 · ERA5再解析による気候平年値
フェニックスでは12か月中9位 · 9月に訪れたい旅行先で1413か所中1273位 · 快適スコア49/100(Fランク)
- 日中
- 39°C
- 夜
- 26°C
- 雨の日
- 2
- 日照
- 11.1 h
- 湿度
- 33%
- 日の長さ
- 12 h

9月のフェニックスについての旅行者の声
Phoenix forum regulars are direct that September is still genuinely hot, not a cooled-off shoulder month: “temps will easily be in the 100s°F,” with many locals steering visitors away entirely until middle/end of September, since it runs “over 100 nearly the entire time” through Memorial Day into fall. The advice for anyone going anyway is specific rather than reassuring: drink constantly, stay in shade, sunscreen including lip balm, and treat the pool and A/C as the actual itinerary rather than an amenity. One small mercy — when rain does come, “it's in the evening,” so it rarely disrupts a day's plans. October gets named as the real payoff month, especially the back half. Our record: 38°C days, 24.6°C nights, 3.8 rain days and 35.3% humidity — genuinely extreme dry heat, matching the “still brutal, don't let October's reputation fool you” read for September specifically.
フェニックスのほかの月
Regulars describe typically dry, sunny days in the 60s-70s Fahrenheit with genuinely chilly evenings, and note that resorts specifically run heated pools this time of year to make swimming a real option despite the season. Our row backs the mild-but-cool read, 20.5C reading as 18C over 8.5C nights feeling 5C, with rain minimal at 19mm across 2.7 days, and humidity down to a dry 52 percent. Regulars are candid that occasional cold spells can drop daytime highs into the 50s Fahrenheit with colder nights, and one long-time Scottsdale resident even reports snow showers three times in ten years around Christmas week - rare, but real. This remains genuinely one of the more popular months here, people specifically traveling in for the mild winter climate. The record: 8.2 hours of sun, an 11.6 kph wind and AQI 54.
April is the month regulars here call their favourite: cool mornings, warm days, and the spring-training crowd gone home, because that fills March and takes the hotel rates with it. Their figures are the mid-eighties by day and mid-fifties at night; ours run a little warmer at 31.4C over 17C, and the number that matters more is 21 percent humidity with a dew point of minus 1.6C - which is why a 31.4C afternoon reads as 29C and why the mornings are genuinely cold. Their day plan follows from it: hike at dawn, pool in the afternoon. Rain is 2.8mm in the whole month. The record: 12 hours of sun, a 15.9 kph wind and AQI 53.
Regulars call February here perfect hiking weather and give highs in the low seventies with overnight lows in the upper forties. Our row agrees almost exactly: 22C by day and 9.3C by night, with 19.2mm of rain across 2.9 days and 9.5 hours of sun. The gap between those two figures is the point - nearly thirteen degrees, on 44 percent humidity and a dew point below zero - so a trail that is pleasant at eight in the morning is cold, and the same trail at two is warm. The other reason to prefer February is the calendar: baseball spring training fills the valley through March, so this is the same weather with fewer people in it. The record: a 13.5 kph wind and AQI 50.
November is the month Phoenix becomes walkable again, and the forum's advice is nonetheless to hike early or late. Even in November the midday sun is hot enough to matter - some days still reach 80F - and the trails people name are up mountains, Camelback, South Mountain and the Phoenix Mountain Preserve, where there is no shade to speak of. North Mountain is the one they hand to anybody wanting easy or mid-range. The other half of the month is the evening: early November is very pleasant but a jacket comes out after dark, and the later in the month you go the chillier it gets. Our row's 26C day against a 12.9C night is that spread. The record: 1.4 precipitation days carrying 10.4mm, humidity 37 percent and 9.2 hours of sun.
地図のフェニックスのカードから自分のメモを追加できます。
フェニックスの気候平年値 — 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月のフェニックスの混雑
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Arizona State Fair、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
フェニックスの天気が良い月
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)。
天気はまずまずフェニックスの天気が最も良いのは2月、3月、11月です — ひと続きのシーズンではなく、別々の時期です。
天気が最高天気はまずまず天気が厳しい
9月のフェニックスのイベント
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。
- 要注意
Extreme heat
5月1日〜10月5日 · 例年Five months over forty degrees with nights that no longer drop below thirty in July. The city is genuinely dangerous outdoors in the afternoon, and it is getting longer every decade. 出典 ↗
- ルール
Heat-day trail closures
5月1日〜9月30日 · 例年休業On excessive heat warning days the city shuts the Camelback, Piestewa and South Mountain trails from eleven to five and fines people who go anyway. Expect several dozen such days a summer. 出典 ↗
- 季節
North American monsoon
6月15日〜9月30日リスクStorms build over the mountains most afternoons from mid-June and break over the valley with an hour of wind and rain. It takes the edge off the heat and puts the humidity up instead.
- 要注意
Haboobs
7月1日〜9月10日 · 例年砂塵シーズン休業Thunderstorm outflows lift a wall of dust hundreds of metres high across the valley in minutes, grounding flights and dropping visibility to nothing. A few a summer, mostly in July and August. 出典 ↗
- 祭り
Arizona State Fair
9月25日〜10月31日 · 例年大きな祭り混雑Five weekends at the fairgrounds west of downtown from late September, which is the first stretch of the year the evenings are bearable outdoors. Light rail is the sane way in. 出典 ↗
近くで開催中のイベント
フェニックスから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。
フェニックスはどこにある?
9月のフェニックス — よくある質問
- 9月はフェニックスを訪れるのに良い時期ですか?
- フェニックスの9月:猛暑、雨が少ない、空気がきれい — おすすめできない時期(午後38°Cの暑さ)。SeasonMapの快適スコアでは、フェニックスの12か月中9位です(49/100)。
- 9月のフェニックスはどんな天気ですか?
- 9月のフェニックスは、平均最高気温38.8°C、最低気温26.2°C、降水量は約12.3 mmで、雨の日はおよそ1.7日です。
- 9月のフェニックスの大気質はどうですか?
- 9月のフェニックスの米国大気質指数(US AQI)は、平均約45です。
300 km圏内:SedonaのDark-sky season(9月15日〜11月20日ごろ)、Grand Canyon National ParkのNorth Rim season(5月15日〜10月15日ごろ)。