Power outage history
Pima County Arizona
1.4hours
without power for the average customer in a typical year, 2018–2025
9th most of 11 in Arizona 78% below the national median
Every day since 2015
Eleven years, one night at a time
Each cell is a day. The brighter it is, the larger the share of Pima's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2023 was the worst well-recorded year, at 3.6 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Pima, hours without power per customer
The record
The biggest outages since 2015
Ranked by customer-hours lost: customers out multiplied by how long they stayed out. Times are local.
| Began | Storm | Peak out | Share | Lasted | 90% restored | Customer-hours |
|---|---|---|---|---|---|---|
| Jul 28, 2023 | Heat | 54,076 | 11% | 28 h | 17 h | 575k |
| Jul 14, 2024 | Thunderstorms | 38,456 | 8% | 16 h | 11 h | 249k |
| Jul 17, 2023 | Thunderstorms | 20,224 | 4% | 11 h | 14 h | 129k |
| Jan 16, 2023 | Winter storm | 20,927 | 4% | 7.2 h | 3.0 h | 110k |
| Jul 11, 2024 | Heat | 20,461 | 4% | 9.5 h | 4.8 h | 76k |
| Nov 12, 2025 | No storm report | 18,508 | 4% | 3.8 h | 2.0 h | 69k |
| Jul 11, 2020 | Wildfire | 21,625 | 4% | 4.0 h | 12 min | 68k |
| Jul 23, 2023 | Wildfire | 13,034 | 3% | 8.2 h | 18 h | 64k |
| Jul 10, 2021 | Thunderstorms | 21,567 | 4% | 4.8 h | 5.5 h | 62k |
| Jul 22, 2021 | Flooding | 14,068 | 3% | 7.0 h | 17 h | 53k |
| Jun 22, 2024 | Heat | 16,549 | 3% | 3.8 h | 2.5 h | 42k |
| Jul 27, 2016 | Thunderstorms | 19,456 | 4% | 3.5 h | 5.8 h | 40k |
| Aug 10, 2017 | Thunderstorms | 11,297 | 2% | 5.8 h | 7.5 h | 39k |
| Jun 26, 2016 | Thunderstorms | 20,466 | 4% | 3.8 h | 5.8 h | 39k |
| Aug 23, 2022 | Thunderstorms | 15,805 | 3% | 3.2 h | 5.0 h | 39k |
| Apr 13, 2019 | No storm report | 13,662 | 3% | 2.5 h | 2.8 h | 32k |
| Feb 8, 2025 | No storm report | 10,157 | 2% | 5.8 h | 2.0 h | 30k |
| Aug 20, 2020 | Flooding | 18,677 | 4% | 2.2 h | 1.0 h | 27k |
| Jul 12, 2023 | Wildfire | 9,997 | 2% | 2.8 h | 1.0 h | 26k |
| Aug 8, 2024 | Thunderstorms | 9,961 | 2% | 2.8 h | 4.5 h | 25k |
| Jul 27, 2018 | Thunderstorms | 12,332 | 3% | 2.5 h | 1.8 h | 21k |
| Jan 27, 2022 | No storm report | 8,346 | 2% | 2.5 h | 2.5 h | 21k |
| Jul 8, 2024 | Heat | 10,197 | 2% | 2.2 h | 2.2 h | 21k |
| Aug 2, 2021 | Thunderstorms | 5,819 | 1% | 3.5 h | 6.0 h | 19k |
| Nov 9, 2016 | No storm report | 13,281 | 3% | 1.5 h | 30 min | 19k |
| Aug 7, 2018 | No storm report | 6,148 | 1% | 3.2 h | 4.8 h | 19k |
| Jul 31, 2023 | Thunderstorms | 8,570 | 2% | 2.8 h | 2.2 h | 19k |
| Sep 26, 2021 | No storm report | 11,512 | 2% | 1.8 h | 3.2 h | 19k |
| Jul 25, 2024 | Thunderstorms | 6,710 | 1% | 2.8 h | 3.0 h | 18k |
| Mar 29, 2022 | Wildfire | 10,107 | 2% | 1.8 h | 1.2 h | 18k |
After the peak
How fast the lights come back
Each line is one major outage, from its peak. The amber line is the typical path.
When it happens
The outage clock
Customer-hours out by month (rings, January innermost) and local hour, 2018–2025.
What was happening
Weather behind the outages
Each outage is matched to NOAA storm reports for Pima from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- Heat 34%
- Thunderstorms 28%
- No storm on record 18%
- Wildfire 9.0%
- Winter storm 6.0%
- Flooding 4.6%
Who keeps the lights on
Utilities serving Pima
As each utility reports to the Energy Information Administration for its whole Arizona territory, not this county alone. Outage minutes include major storm days.
| Utility | Type | Outage min / yr | Excl. major storms | Outages / yr | Residential ¢/kWh | Customers |
|---|---|---|---|---|---|---|
| Arizona Public Service Co | Investor Owned | 73 | 73 | 0.84 | 17.0 | 1.3M |
| Tucson Electric Power Co | Investor Owned | 42 | 42 | 0.65 | 14.9 | 416k |
| Trico Electric Cooperative Inc | Cooperative | 90 | 66 | 0.73 | 14.3 | 54k |
| Sulphur Springs Valley E C Inc | Cooperative | 92 | 83 | 0.83 | 14.6 | 46k |
| Tohono O'Odham Utility Authority | AZ | – | – | – | – | 31k |
| USBIA-San Carlos Project | Federal | – | – | – | 16.4 | 12k |
| Ajo Improvement Co | Investor Owned | – | – | – | 13.5 | 808 |
| WAPA-- Western Area Power Administration | Federal | – | – | – | – | – |
EIA Form 861, latest year each utility reported. Outage minutes are SAIDI, the yearly minutes the average customer goes without power; outages a year are SAIFI.
Next door
Neighbouring counties
About these numbers
Notes
Outages come from the EAGLE-I record of utility outage maps collected every 15 minutes by Oak Ridge National Laboratory. Hours without power are customer-hours divided by the county's 492,744 electricity customers. Averages use well-covered years from 2018. Outages shorter than 15 minutes, and utilities that publish no outage map, are not in the record, so these figures understate the total. How every number is made →