Tucson Climate and Water

The climate, in numbers

These are the long-term normals from NOAA, the 1991 to 2020 record, which is the fair baseline:

• Rain: 10.61 inches a year
• June average high: 101.2 degrees
• July average high: 100.2 degrees
• January average high: 66.5 degrees, average low 40.8 degrees
• Days at 100 degrees or more: about 68 a year
• Days at 90 degrees or more: about 158 a year
• Nights at freezing or below: about 12 a year
• Sunshine: about 3,800 hours a year

Tucson sits at about 2,400 feet of elevation, which is why it runs several degrees cooler than Phoenix. In one recent comparison through early October 2025, Tucson had about 78 days at 100 or more while Phoenix had about 122. Hot is hot, but the two cities are not the same hot.

The part the normals do not tell you

Recent years have run hotter than the 1991 to 2020 baseline, and you should plan on the recent version, not the average. In 2024, Tucson set a record with 112 days at 100 degrees or more. In 2026, the first 100-degree day arrived on March 19, the earliest on record, and the year finished the monsoon season with 77 days at 100 or more. Summer is also starting earlier than it used to.

What this means in daily life: from June into September, you plan your day around the heat. Yard work, walks, and hikes happen early. Errands happen in the morning or after the sun drops. Pools, shade, and a good AC unit are not extras. Then October arrives, and you get about seven months of weather that people in most of the country would pay extra for. Locals will tell you summer is the tax and winter is the refund. That is about right.

Monsoon

The official monsoon season runs June 15 to September 30. A normal season brings about 5.69 inches of rain, close to half the year's total. In 2026 the season delivered 5.76 inches, right at normal.

Here is how it works in practice. A summer day builds heat until mid afternoon, clouds pile up over the mountains, and a storm rolls through with wind, dust, lightning, and hard rain that can drop an inch in an hour. Then it clears, the temperature falls 15 or 20 degrees, and the desert smells like creosote. It is the best part of summer.

The rules that come with it: never drive through a flooded wash (Arizona has a law about it, and people die ignoring it), expect some streets to close briefly during big storms, and know that dust storms can cut visibility to near zero on the highways. You will get the rhythm within one season.

Water: the question everyone asks

Short answer: Tucson is not running out of water, and the long answer is more interesting than the headline.

Tucson Water holds a Designation of Assured Water Supply from the state. The current designation runs through 2037 and reflects the state's 100-year sufficiency standard. In the city's own September 2026 water advisory minutes, the numbers were about 225,000 acre-feet of available resources against about 95,000 acre-feet of current drinking water demand. The city uses far less than its full supply. Tucson has been banking Colorado River water underground for decades, in recharge basins in Avra Valley west of town, and that stored water is a real cushion.

The supply mix is roughly 70 percent Colorado River water through the Central Arizona Project canal, about 15 percent groundwater, and about 15 percent recycled water. Conservation is a big part of why the math works: Tucson uses about the same total water it did decades ago with far more people in it.

Now the honest nuance, because you will read about it anyway. Colorado River cuts are real. Tucson's canal allocation is expected to fall about 14 percent in 2027, roughly 20,000 acre-feet. The city's planning treats most of that as offset by the banked water, and there is more uncertainty about 2028 and beyond. The fair way to say it: the supply is shifting, the city planned for the shift better than most desert cities, and water bills may rise over time. That is a different picture from running dry, and it is the true one.

One caution. The assured supply rules work differently for rural lots and homes on wells outside the city's service area. If you fall for a property outside Tucson Water's system, ask where the water comes from and get the answer in writing before you buy.

Sources: City of Tucson Citizens' Water Advisory Committee minutes, September 2026; Arizona Department of Water Resources data. Climate: NOAA 1991 to 2020 normals; recent-year figures from National Weather Service Tucson records as compiled by Tucson Daily Brief, accessed November 2026. Full list on the sources page.