County annual report · FIPS 04019
2021 Pima County, AZ Power Outage Report
In 2021, customers in Pima County, AZ went without power for an average of 1.9 hours, a total of 923K customer-hours (Arizona average 1.9 hours). That ranks 7th worst of 13 Arizona counties and 2275th of 2,974 nationally.
Compared with AZ, the US and 2020
Coverage line is EAGLE-I's share of Arizona customers tracked each year.
Biggest outages in Pima County, 2021
The 10 outage episodes with the most customers out at once. Times are UTC.
| # | Started (UTC) | Ended (UTC) | Duration | Peak out | Customer-hours |
|---|---|---|---|---|---|
| 1 | December 2, 2021 04:00 | December 13, 2021 20:45 | 11d 16h | 27,249 | 56K |
| 2 | January 25, 2021 21:30 | January 28, 2021 14:30 | 2d 17h | 24,183 | 75K |
| 3 | July 7, 2021 16:30 | July 28, 2021 20:45 | 21d 4h | 21,567 | 312K |
| 4 | September 22, 2021 16:15 | October 14, 2021 02:30 | 21d 10h | 11,512 | 67K |
| 5 | May 24, 2021 15:45 | June 19, 2021 05:30 | 25d 13h | 7,921 | 65K |
| 6 | July 29, 2021 21:30 | July 31, 2021 07:15 | 1d 9h | 7,815 | 9,791 |
| 7 | August 12, 2021 06:30 | August 16, 2021 20:30 | 4d 14h | 6,070 | 20K |
| 8 | July 2, 2021 19:45 | July 6, 2021 13:30 | 3d 17h | 6,069 | 21K |
| 9 | August 2, 2021 18:15 | August 4, 2021 17:15 | 1d 23h | 5,819 | 34K |
| 10 | May 5, 2021 15:45 | May 5, 2021 20:15 | 4h 30m | 4,971 | 7,403 |
Outage episodes by size in 2021: 116 reached 100+ customers, 58 reached 1,000+ customers, 4 reached 10,000+ customers.
Utility reliability filed with the EIA
SAIDI (average outage time per customer) and SAIFI (average interruptions per customer) that utilities serving Pima County reported on EIA Form 861 for 2021, or their most recent earlier filing. Utility-wide figures, not county-specific.
| Utility | EIA year | SAIDI | SAIFI | SAIDI excl. major events | SAIFI excl. major events |
|---|---|---|---|---|---|
| Arizona Public Service Co | 2021 | 1.8 hrs | 1.02 | 87 min | 0.89 |
| Sulphur Springs Valley E C Inc | 2021 | 71 min | 0.67 | 52 min | 0.67 |
| Trico Electric Cooperative Inc | 2021 | 1.6 hrs | 0.75 | 57 min | 0.46 |
| Tucson Electric Power Co | 2021 | 1.7 hrs | 0.91 | - | - |
| WAPA-- Western Area Power Administration | - | - | - | - | - |
| USBIA-San Carlos Project | - | - | - | - | - |
| Tohono O'Odham Utility Authority | - | - | - | - | - |
| Ajo Improvement Co | - | - | - | - | - |
About this data
- Outage figures come from DOE/ORNL EAGLE-I, which records customers out by county every 15 minutes. EAGLE-I tracked about 91% of Arizona's customers in 2021; utilities it does not see are not counted.
- Hours per customer = outage customer-minutes ÷ 492,744 customers (ORNL modeled county customer count), including major storm days. It is comparable across counties but is not the SAIDI a utility files.
- An outage event is a continuous stretch with customers out; counts at 100, 1,000 and 10,000+ use its peak.
- Years loaded: 2015–2025. Pima County has data for 2015–2025.
Cite this report
MassOutage (massoutage.com), Pima County, AZ annual power outage report, 2021, data as of Oct 3, 2026 02:41 UTC, sources: DOE EAGLE-I (https://eagle-i.doe.gov/); EAGLE-I modeled customer counts (MCC) (https://figshare.com/); EIA Form 861 (utility reliability) (https://www.eia.gov/electricity/data/eia861/). https://massoutage.com/reports/2021/arizona/pima-county