temperature · United States
Phoenix, Arizona
July mean daily maximum
Modelled demonstration series · not observed data
This is not a hot July, it is a July that the twentieth-century record has no slot for. Nights are the real damage: when the daily maximum sits this high for weeks, the overnight low never drops far enough for a body, or a building, to shed the previous day's heat. Emergency rooms feel this before thermometers make the news.
75 years, modelled
Same reading, two normals
| Normal | Mean | σ | Pct | Return |
|---|---|---|---|---|
| 1951–1980 | 40.2 °C | +4.60σ | >99.999th | 1 in 470,000 years |
| 1991–2020 | 41.5 °C | +2.43σ | 99.25th | 1 in 130 years |
Today would be the highest value in the entire 75-year modelled series. Past the series' standing high of 44.5 °C (2019). Nothing about the reading changes between rows — only the yardstick.
The season here
July is the peak of the Sonoran summer. A hot July here is expected; the question is only how far past expected it goes.
Where this series comes from
MODELLED SERIES — not observed. Parameters set from published Phoenix Sky Harbor July climatology (1951–1980 mean daily max near 40 °C, interannual σ near 1 °C, warming of roughly a third of a degree per decade including the urban heat-island contribution). The 75 annual values are synthesised by the seeded generator. Population is a rounded metropolitan estimate.
Every number on this page comes from a modelled series: 75 annual values synthesised by a seeded generator from published climatological parameters for Phoenix, Arizona. It shows how anomaly reasoning works. It is not a measurement and must not be cited as one.
How to read σ
σ counts standard deviations from this place's own normal. The sigma guide · return periods.
More temperature stations
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