Introduction:
One of the reasons why people call Phoenix home or visit is the sunshine and weather. Phoenix experiences 300 or more sunny days and most of the year the temperatures are mild. However, that can’t be said about the summer in Phoenix.
In one word, Phoenix summer’s can be summed up in one word – relentless.
Phoenix Summer Temperatures: Average Temperatures
The data used in this post comes from the the National Weather Service with some additional calculations on my part.
If you consider Summer to be the months of June through August, then the average high temperature since 2000 in Phoenix is 105.89℉.
However, to get a better picture of the Phoenix Summer temperatures, I expanded it to be May through September. You will understand better why I included May and September throughout this post. When factoring in those two months, the average temperature since 2000 is 102.79℉. Much cooler, huh?
Besides expanding summer by a few months, I also am only taking a look at the data from 2010.
Let’s breakdown Phoenix Summer Temperatures by month.
| MONTH | AVERAGE HIGH | AVERAGE LOW |
| MAY | 94.38℉ | 69.04℉ |
| JUNE | 106.18℉ | 80.31℉ |
| JULY | 106.70℉ | 85.20℉ |
| AUGUST | 105.66℉ | 83.91℉ |
| SEPTEMBER | 100.99℉ | 78.57℉ |
For most of the United States, they would be happy with a day or two at May’s average high. Unfortunately for Phoenix, that is only the beginning.
Below are tables for the monthly average high temperatures and low temperatures since 2010:
Phoenix Monthly Average High Temperatures: 2010 – Present
| YEAR | MAY | JUNE | JULY | AUGUST | SEPTEMBER |
| 2010 | 91.32 | 104.60 | 106.58 | 104.65 | 104.10 |
| 2011 | 91.45 | 104.27 | 106.94 | 108.97 | 103.27 |
| 2012 | 98.16 | 106.50 | 104.61 | 105.77 | 99.2 |
| 2013 | 96.00 | 108.40 | 105.68 | 105.26 | 99.50 |
| 2014 | 95.52 | 106.23 | 107.06 | 102.29 | 99.20 |
| 2015 | 90.13 | 105.93 | 105.13 | 107.68 | 100.33 |
| 2016 | 91.97 | 107.43 | 108.26 | 102.87 | 97.50 |
| 2017 | 94.55 | 107.93 | 106.16 | 105.42 | 99.30 |
| 2018 | 96.55 | 105.40 | 107.55 | 104.97 | 103.50 |
| 2019 | 87.84 | 104.03 | 108.23 | 108.19 | 99.53 |
| 2020 | 99.68 | 104.97 | 109.84 | 110.74 | 104.07 |
| 2021 | 96.23 | 108.20 | 103.65 | 103.23 | 100.07 |
| 2022 | 97.61 | 106.50 | 107.48 | 103.48 | 101.70 |
| 2023 | |||||
| Average | 94.38 | 106.18 | 106.70 | 105.66 | 100.87 |
Phoenix Monthly Average Low Temperatures: 2010 – Present
| YEAR | MAY | JUNE | JULY | AUGUST | SEPTEMBER |
| 2010 | 65.16 | 77.87 | 86.87 | 83.39 | 78.90 |
| 2011 | 66.06 | 77.27 | 83.48 | 87.55 | 79.47 |
| 2012 | 70.87 | 81.00 | 83.16 | 84.87 | 78.10 |
| 2013 | 71.87 | 81.20 | 85.71 | 84.13 | 77.90 |
| 2014 | 70.77 | 80.13 | 85.90 | 80.84 | 78.80 |
| 2015 | 67.35 | 82.10 | 84.19 | 85.61 | 79.40 |
| 2016 | 67.84 | 82.13 | 86.00 | 80.87 | 75.67 |
| 2017 | 69.10 | 81.37 | 83.84 | 82.58 | 76.40 |
| 2018 | 70.48 | 79.30 | 85.52 | 83.10 | 80.20 |
| 2019 | 64.65 | 78.10 | 85.13 | 85.39 | 78.70 |
| 2020 | 72.68 | 79.10 | 88.03 | 87.39 | 78.97 |
| 2021 | 70.03 | 82.47 | 83.71 | 81.90 | 78.37 |
| 2022 | 70.65 | 81.93 | 86.00 | 83.19 | 80.50 |
| 2023 | |||||
| Average | 69.04 | 80.31 | 85.20 | 83.91 | 78.57 |
While average temperatures give you a glimpse of the phoenix temperatures, I don’t feel it tells the entire story. Let’s take a closer look at how hot it really is.
Number of Days Phoenix High Temperature Greater than 100℉: 2010 – Present
Let’s dig into how many days in a month did Phoenix experience a high temperature greater than 100℉
Believe it or not, Phoenix will generally see its first 100℉ day on May 6th. Since 1950, the earliest day was March 26, 1988 and the latest on June 13, 1971.
In the table below, I have the number of days for each month. In addition, I calculated the average number of days per month at the bottom.
For the months of June through August, Phoenix will experience a 100℉ or more on 90% of the days. Meanwhile, you will still see many 100℉ days in September. On average, the last 100℉ day occurs on September 30th. Since 1950, the earliest last day was September 7, 1961 with the latest on October 27, 2016.
| YEAR | MAY | JUNE | JULY | AUGUST | SEPTEMBER |
| 2010 | 2 | 25 | 28 | 25 | 25 |
| 2011 | 6 | 23 | 30 | 31 | 24 |
| 2012 | 12 | 30 | 27 | 25 | 16 |
| 2013 | 9 | 30 | 28 | 29 | 16 |
| 2014 | 11 | 30 | 30 | 22 | 17 |
| 2015 | 4 | 25 | 30 | 30 | 17 |
| 2016 | 4 | 27 | 30 | 23 | 14 |
| 2017 | 12 | 27 | 28 | 29 | 13 |
| 2018 | 12 | 28 | 30 | 30 | 26 |
| 2019 | 1 | 25 | 30 | 31 | 15 |
| 2020 | 16 | 26 | 30 | 31 | 25 |
| 2021 | 11 | 28 | 26 | 20 | 19 |
| 2022 | 11 | 29 | 28 | 25 | 20 |
| 2023 | |||||
| Average | 8.54 | 27.15 | 28.85 | 27.00 | 19.00 |
With the dryer climate, 100℉ is manageable and doesn’t feel as bad as other cities in the US with high temperatures combined with high humidity.
However, that changes a little bit when the temps start creeping up to 110℉ or more.
Number of Days Phoenix High Temperature Greater than 110℉: 2010 – Present
The temperatures start to climb in June.
Phoenix sees its first 110℉ day on June 13th. Since 1950, the earliest day was May 8, 1989 and the latest on July 8, 1956.
In the table below, I have the number of days for each month. In addition, I calculated the average number of days per month at the bottom.
For the months of June through August, Phoenix will experience a 110℉ or more on 26.5% of the days. You may still see a day or two in September over 110℉. On average, the last 110℉ day occurs on August 19th. Since 1950, the earliest last day was June 23, 1955 with the latest on September 19, 2010.
| YEAR | MAY | JUNE | JULY | AUGUST | SEPTEMBER |
| 2010 | 0 | 5 | 10 | 6 | 2 |
| 2011 | 0 | 9 | 9 | 13 | 0 |
| 2012 | 0 | 7 | 4 | 10 | 0 |
| 2013 | 0 | 8 | 7 | 7 | 3 |
| 2014 | 0 | 2 | 7 | 1 | 0 |
| 2015 | 0 | 11 | 1 | 8 | 0 |
| 2016 | 0 | 12 | 15 | 3 | 0 |
| 2017 | 0 | 11 | 8 | 4 | 2 |
| 2018 | 0 | 5 | 10 | 7 | 0 |
| 2019 | 0 | 4 | 11 | 12 | 2 |
| 2020 | 2 | 7 | 19 | 22 | 3 |
| 2021 | 0 | 11 | 6 | 4 | 1 |
| 2022 | 0 | 6 | 14 | 1 | 1 |
| 2023 | |||||
| Average | 0.15 | 7.54 | 9.31 | 7.54 | 1.23 |
At this point, you have gotten use to the heat and know how to manage it. Unfortunately, it doesn’t just stop there. Let’s take a look at the number of days of 115℉ or more.
Number of Days Phoenix High Temperature Greater than 115℉: 2010 – Present
We are now getting close to record setting territory when talking about temperatures hitting 115℉ or greater.
As you can see by the chart below, there aren’t too many days on average. However, on a few occasions, you will see a heat wave that increases that number.
| YEAR | MAY | JUNE | JULY | AUGUST | SEPTEMBER |
| 2010 | 0 | 0 | 0 | 0 | 0 |
| 2011 | 0 | 1 | 1 | 1 | 0 |
| 2012 | 0 | 0 | 0 | 3 | 0 |
| 2013 | 0 | 3 | 0 | 0 | 0 |
| 2014 | 0 | 0 | 1 | 0 | 0 |
| 2015 | 0 | 1 | 0 | 2 | 0 |
| 2016 | 0 | 3 | 0 | 0 | 0 |
| 2017 | 0 | 5 | 1 | 0 | 0 |
| 2018 | 0 | 0 | 4 | 0 | 0 |
| 2019 | 0 | 0 | 1 | 1 | 0 |
| 2020 | 0 | 0 | 6 | 7 | 1 |
| 2021 | 0 | 6 | 0 | 1 | 0 |
| 2022 | 0 | 0 | 1 | 0 | 0 |
| 2023 | |||||
| Average | 0 | 1.46 | 1.15 | 1.15 | 0.70 |
A typical summer will see one or two stretches of extremely high temperatures. Luckily, it isn’t very humid compared to other places in the US and it helps make the heat tolerable.
While the high temperatures get all the press, it wasn’t the thing to surprised by about Phoenix Summer Temperatures. You expect Phoenix to be hot, but what I wasn’t prepared for is how hot it remains at night.
Does It Ever Cooldown During The Summer?
Part of the title to this post is the word relentless. That is how I feel about the Phoenix Summer. As mentioned, it isn’t so much the heat. It is hot in a lot of places.
What is hard for me is that you don’t get relief at night. I am used to enjoying cooler temperatures when the sun would go down at night. That isn’t the case in Phoenix.
As the table below shows, the average low is more than 80℉ for the months of June through August with September’s low only 78℉.
| MONTH | AVERAGE LOW |
| JUNE | 80.31℉ |
| JULY | 85.20℉ |
| AUGUST | 83.91℉ |
| SEPTEMBER | 78 |
There will be nights during the summer that it will still be 100℉ at midnight.
So how hot can the low’s be, let’s check it out.
Number of Days Phoenix Low Temperature Greater than 90: 2010 – Present
Just like hitting more than 115℉ for the high happens on average a little over a day for June, July, and August. You can expect to see even more nights with a temperature greater than 90℉ as you can see from the chart below.
While you don’t get much relief on these nights, you do feel a sense of relief from the intense heat from the sun.
| YEAR | MAY | JUNE | JULY | AUGUST | SEPTEMBER |
| 2010 | 0 | 0 | 10 | 3 | 0 |
| 2011 | 0 | 1 | 2 | 8 | 2 |
| 2012 | 0 | 1 | 3 | 7 | 0 |
| 2013 | 0 | 2 | 8 | 5 | 0 |
| 2014 | 0 | 0 | 4 | 0 | 0 |
| 2015 | 0 | 2 | 0 | 5 | 0 |
| 2016 | 0 | 3 | 7 | 0 | 0 |
| 2017 | 0 | 4 | 2 | 1 | 0 |
| 2018 | 0 | 1 | 8 | 5 | 0 |
| 2019 | 0 | 0 | 9 | 2 | 1 |
| 2020 | 0 | 0 | 16 | 12 | 0 |
| 2021 | 0 | 4 | 4 | 1 | 0 |
| 2022 | 0 | 3 | 8 | 0 | 0 |
| 2023 | |||||
| Average | 0 | 1.62 | 6.23 | 3.77 | 0.23 |
Now let’s take a look at days where the low is greater than 85℉.
Number of Days Phoenix Low Temperature Greater than 85: 2010 – Present
It is probably a safe bet to say that some people in the US would be ecstatic about an 85℉ day if it was their high.
In Phoenix, you can expect a large portion of the lows in July to exceed 85℉ and almost half of August. In addition, you will probably see a few nights in early September too.
| YEAR | MAY | JUNE | JULY | AUGUST | SEPTEMBER |
| 2010 | 0 | 2 | 22 | 16 | 4 |
| 2011 | 0 | 7 | 14 | 26 | 8 |
| 2012 | 0 | 9 | 15 | 18 | 4 |
| 2013 | 0 | 3 | 20 | 15 | 8 |
| 2014 | 0 | 4 | 20 | 4 | 2 |
| 2015 | 0 | 15 | 18 | 19 | 2 |
| 2016 | 0 | 9 | 23 | 5 | 1 |
| 2017 | 0 | 8 | 15 | 11 | 8 |
| 2018 | 0 | 3 | 18 | 12 | 6 |
| 2019 | 0 | 2 | 17 | 21 | 8 |
| 2020 | 0 | 3 | 25 | 22 | 5 |
| 2021 | 0 | 13 | 17 | 13 | 3 |
| 2022 | 0 | 10 | 17 | 14 | 9 |
| 2023 | |||||
| Average | 0 | 6.77 | 18.54 | 15.08 | 5.23 |
The hot Phoenix Summer Temperatures is something you would have to get use to if you decide to live or visit this great city.
If you are thinking about looking to move to the greater Phoenix area, I would be happy to help you. Feel free to search for homes for sale.
