Phoenix, AZ weather in September
September in Phoenix: very hot and dry. Highs 100°F, lows 78°F, rain on about 3 days. Midday heat is the main thing to plan around.
- Normal high
- 100°F
- Normal low
- 78°F
- Wet days
- 3
- 0.6 in total
- Muggy days
- 2
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 104°F | 96°F |
| Normal low | 82°F | 73°F |
| Chance of a wet day | 12% | 7% |
| Sunrise / sunset | 6:02 am / 6:54 pm | 6:22 am / 6:14 pm |
| Daylight | 12.9 h | 11.9 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Arizona time (no daylight saving)).
A typical September day
- 6 am79°Fdew point 54°F
- 9 am85°Fdew point 53°F
- Noon94°Fdew point 52°F
- 3 pm98°Fdew point 49°F
- 6 pm97°Fdew point 48°F
- 9 pm90°Fdew point 50°F
NOAA hourly normals (local standard time) from Phoenix Sky Harbor Intl Airport (4 mi away); average wind 6 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F0 of 30
- Hot dayshigh 90°F or more28 of 30
- Muggy daysdaily mean dew point 65°F or more2 of 30
- Wet daysat least 0.01 in of rain or melted snow3 of 30
- Notable rainat least 0.10 in1 of 30
- Freezing nightslow 32°F or below0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 0.6 in; a dry September brings about 0.06 in and a wet one about 0.7 in (25th and 75th percentiles). Days with half an inch or more are rare.
How September varies from year to year
- Warmest September, 1991-20202001: average high 105°F
- Coolest September1996: average high 95°F
- Wettest September2014: 5.1 in
- Driest September2001: no measurable precipitation
- Highest reading115°F (September 5, 2020)
- Lowest reading62°F (September 25, 2017)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 105°F | 100°F | 89°F |
| Normal low | 84°F | 78°F | 66°F |
| Wet days | 5 | 3 | 2 |
| Comfortable days | 0 | 0 | 5 |
| Daylight | 13.4 h | 12.4 h | 11.3 h |
Highs change by -5°F from August and -11°F into October.
Nearby alternatives in September
- Cooler: Sedona, AZ100 mi · high 89°F · 5 wet days
How Phoenix ranks in September
- Normal high7th warmest of 378 cities; 5th of 13 in Arizona
- Wet days70th driest of 378
- Comfortable days319th most of 342
What to pack for Phoenix in September
- Light, breathable clothing – highs near 100°F and about 2 muggy days
Heating and cooling
September has 0 heating degree days and 727 cooling degree days (base 65°F), 13% of the year's total heating and cooling demand.
Questions
How hot is Phoenix in September?
The normal high is 100°F and the normal low is 78°F. From 1991 to 2020 the hottest September reading was 115°F (September 5, 2020).
Does it rain a lot in Phoenix in September?
About 3 days in September have at least 0.01 in of precipitation, and the normal total is 0.6 in. The wettest September in 1991-2020 was in 2014 (5.1 in); the driest was in 2001, with no measurable precipitation.
Is September a good time to visit Phoenix?
September ranks 12th of 12 months on our comfort score for Phoenix (33 out of 100). It has almost no comfortable days and about 28 days at 90°F or hotter. The best months are January and February.
Where the numbers come from
- Temperature, rain, frost dates and humidity and wind by hour: Phoenix Sky Harbor Intl Airport (USW00023183), 4.3 mi ESE of the city center, 1,107 ft . NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: Tempe ASU (USC00028499), 8.9 mi E of the city center, 1,167 ft (79 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Phoenix Sky Harbor Intl Airport (722780-23183), 4.3 mi ESE of the city center, 1,113 ft . Hourly observations, 1991-2020.
- Not available for this location: cloud cover (no station close enough or similar enough in elevation).