Climateby Month

Mesa, AZ weather in September

NOAA 1991-2020 normals and daily records · Mesa all year

Expect very hot, mostly dry weather in Mesa in September, with highs near 100°F and lows near 78°F. Rain falls on about 3 days. Plan outdoor time for mornings and evenings.

Normal high
100°F
Normal low
78°F
Wet days
3
0.7 in total
Muggy days
2
dew point 65°F+

How September changes from start to finish

Normal values at the start and end of September
September 1September 30
Normal high104°F96°F
Normal low82°F73°F
Chance of a wet day14%9%
Sunrise / sunset6:01 am / 6:53 pm6:20 am / 6:13 pm
Daylight12.9 h11.9 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

  1. 6 am79°Fdew point 54°F
  2. 9 am85°Fdew point 53°F
  3. Noon94°Fdew point 52°F
  4. 3 pm98°Fdew point 49°F
  5. 6 pm97°Fdew point 48°F
  6. 9 pm90°Fdew point 50°F

NOAA hourly normals (local standard time) from Phoenix Sky Harbor Intl Airport (11 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 in2 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 0.7 in; a dry September brings about 0.1 in and a wet one about 0.8 in (25th and 75th percentiles). About 1 day brings half an inch or more.

How September varies from year to year

  • Warmest September, 1991-20202001: average high 105°F
  • Coolest September1996: average high 95°F
  • Wettest September2014: 5.5 in
  • Driest September2000: 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

AugustSeptemberOctober
Normal high105°F100°F89°F
Normal low84°F78°F66°F
Wet days533
Comfortable days005
Daylight13.4 h12.4 h11.3 h

Highs change by -5°F from August and -11°F into October.

Nearby alternatives in September

How Mesa ranks in September

  • Normal high6th warmest of 378 cities; 4th of 13 in Arizona
  • Wet days72nd driest of 378
  • Comfortable days317th most of 342

What to pack for Mesa 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 Mesa 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 Mesa in September?

About 3 days in September have at least 0.01 in of precipitation, and the normal total is 0.7 in. The wettest September in 1991-2020 was in 2014 (5.5 in); the driest was in 2000, with no measurable precipitation.

Is September a good time to visit Mesa?

September ranks 12th of 12 months on our comfort score for Mesa (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, frost dates and humidity and wind by hour: Phoenix Sky Harbor Intl Airport (USW00023183), 11 mi W of the city center, 1,107 ft (135 ft lower than the city). NOAA normals and daily records, 1991-2020.
  • Rain: Mesa (USC00025467), 0.8 mi SSE of the city center, 1,235 ft . NOAA normals and daily records, 1991-2020.
  • Snowfall and snow depth: Tempe ASU (USC00028499), 5.7 mi W of the city center, 1,167 ft (75 ft lower than the city). NOAA normals and daily records, 1991-2020.
  • Daily humidity and wind: Phoenix Sky Harbor Intl Airport (722780-23183), 11 mi W of the city center, 1,113 ft (129 ft lower than the city). Hourly observations, 1991-2020.
  • Not available for this location: cloud cover (no station close enough or similar enough in elevation).