Life in the Desert

Heat, water, sky, and power in the Tucson metro, measured. The numbers today, the season against prior years, and the long record, all from official instruments and filings. Updated 4:20 PM MST on Sept. 9, 2026.

The Desert Today

Right now at the airport

99°

as of 3:45 PM; normal high today 97°

Lake Mead

1,038.9 ft

down 17.5 ft in a year

Air quality

Good, driven by ozone

TEP demand

2,703

MW peak on Sept. 8; solar peaked at 536 MW

Jump to: Heat · Water · Sky · Power

Heat

On Sept. 8 Tucson reached 97° against a normal high of 97° and a record of 105° (set in 1924, 1990). The overnight low was 78° (normal 73°).

Through Sept. 7, 2026 has had 76 days at or above 100°, 34 at or above 105°, and 1 at or above 110°. By the same date, that ranks 5th of the 80 years on record.

The first 100-degree day of 2026 was March 19. Before this year, the earliest on record was April 11 in 2025.

Averaged over the year so far, highs are running +3.3° against the 1991–2020 normal and overnight lows +3.6°.

Days at or above 100° through Sept. 7 of each year, last 12 years. Dashed line: the record pace. Source: NOAA daily summaries, Tucson International Airport.

The first 100-degree day of each year since 1946. Source: NOAA.

Every daily high in 2026 against the 1991–2020 normal. Source: NOAA.

Average overnight low for June through August, each year since 1946. Overnight heat is the half of the story the daytime record misses. Source: NOAA.

Water

Lake Mead stood at 1,038.93 feet on Sept. 8, down 17.5 ft in a year, below the Tier 1 shortage line of 1,075 feet. Its lowest point in the record is 670.00 feet, on Feb. 2, 1935. Full pool is 1,229 feet.

Lake Mead's elevation, monthly mean, since Hoover Dam began filling. Dashed lines mark the Colorado River shortage tiers that govern Arizona's supply. Source: Bureau of Reclamation.

The monsoon (June 15 to Sept. 30) has delivered 4.97 inches at the airport so far this season, against a normal of 4.79 inches to the same date. A full normal season is 6.06 inches.

Running monsoon rainfall total at the airport: 2026 against 2025 and normal. Source: NOAA.

Total monsoon-season rainfall (June 15 to Sept. 30) at Tucson International, every year since 1950. Source: NOAA.

Of the county flood-control district's 128 rain gauges, 2 recorded rain in the last 24 hours. The wettest in the last 30 days:

Gauge	24 h	7 days	30 days
Florida Canyon Santa Cruz Basin	0.00	0.43	3.31
White Tail Campground - Sabino Basin	0.04	0.12	2.95
Santa Cruz River near Tubac	0.00	0.75	2.56
Massingale Detention	0.00	0.39	2.36
Haystack Mountain - Cienega Basin	0.04	0.20	2.24

Flow in the washes right now (USGS, provisional):

Santa Cruz River at downtown Tucson: 0 cubic feet per second
Rillito Creek at Dodge Boulevard: 0 cubic feet per second
Santa Cruz River at Cortaro: 34 cubic feet per second

Tucson Water has 5 active service advisories right now. In the last 30 days it posted 74, of which 51 were unplanned outages. Tucson Water publishes only the live list; this archive has kept every advisory since June 2026. Other utilities in the metro publish no live feed.

Planned Outage
Unplanned Outage — to repair leaking main
Unplanned Outage — to repair a leaking main
Informational — valve/hydrant maintenance
Informational — valve/hydrant maintenance

Tucson Water outage and pressure advisories per week. Source: Tucson Water's advisory feed, archived by Tucson Daily Brief.

Sky

Air quality in Tucson right now (Arizona Department of Environmental Quality monitors, via AirNow):

OZONE: 41 — Good
PM10: 23 — Good
PM2.5: 31 — Good

Observed 3 p.m. Sept. 9. Preliminary data.

Sunrise today 6:04 a.m., sunset 6:37 p.m.: 12 hours 33 minutes of daylight. The UV index forecast for Sept. 10 is 10 (very high).

Rain since Jan. 1: 7.48 inches at the airport, against a normal of 7.52 to this date.

Weather alerts

No National Weather Service alerts are in effect for the Tucson metro.

Power

On Sept. 8, demand on Tucson Electric Power's system peaked at 2,703 megawatts at 6 p.m.. Solar generation on TEP's own system peaked at 536 MW at noon.

This year's peak so far is 3,416 MW, July 24, 2026, at 6 p.m.. The highest hour in the archive since 2015 is 4,147 MW, July 11, 2020, at 5 p.m.. The record solar hour is 645 MW, April 17, 2026, at 11 a.m..

One day on TEP's grid, hour by hour: total demand and the utility's own solar output. Imports and rooftop solar are not shown. Source: U.S. Energy Information Administration, Form 930.

The highest single hour of demand each year on TEP's system. Source: EIA Form 930.

Where TEP's own generation comes from

Coal

Natural gas

Solar

Wind, hydro, storage, other

Shares are of electricity TEP generated itself, not of what customers used; purchased power and rooftop solar are outside this measure. Source: EIA Form 930.

About these numbers

Temperatures and rain are the official record at Tucson International Airport from NOAA and the National Weather Service. Lake Mead is the Bureau of Reclamation's daily reading at Hoover Dam. Wash flows are provisional USGS gauge data. Rain gauges are the Pima County Regional Flood Control District's network. Air quality is the state's monitors, published through AirNow; preliminary until verified. Grid data is TEP's hourly filing to the U.S. Energy Information Administration. Water advisories are Tucson Water's live feed, which we archive because the utility does not. Every agency publishes a snapshot; Tucson Daily Brief keeps the history. Corrections: talk to us.

No AI model was used on this page: every figure is a measurement from the National Weather Service, NOAA, the Bureau of Reclamation, the U.S. Geological Survey, the Pima County Regional Flood Control District, AirNow, the U.S. Energy Information Administration, and Tucson Water, archived and charted by Tucson Daily Brief's own code. Updated 4:20 PM MST on September 9, 2026. Read more about how this is made.