Phoenix weather in September

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.

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.