Pima County Power Outage History
2015–2025 · Arizona
Top 20% most reliable nationally — infrequent, short outages. How grades are calculated
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Feb 1, 2016 | 6 hrs | 55,764 (11%) | Winter Storm |
| Jul 29, 2023 | 51 hrs | 54,076 (11%) | Excessive Heat |
| Dec 20, 2017 | 1 hrs | 43,225 (9%) | Unnamed event |
| Jul 15, 2024 | 54 hrs | 38,456 (8%) | Excessive Heat |
| Feb 17, 2016 | 1 hrs | 32,778 (7%) | Unnamed event |
Over the 11 years from 2015 to 2025, Pima County recorded 1,722 distinct power outage events, averaging 2.0 hours per event.
The single worst outage on record in Pima County started February 1, 2016 (Winter Storm), lasting 6 hours and leaving up to 55,764 customers without power (11% of the county) at its peak.
July has historically been the worst month for outages in Pima County, with 277 events recorded during that month across the dataset.
Based on this history, Pima County earns a Reliability Grade of A, placing it in the 86th percentile nationally for grid reliability (higher percentile = more reliable).
Sized for Pima County's outage profile
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Outage-prep kit
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Similar counties in Arizona
Counties with the closest reliability grade and national percentile to Pima County.
| County | Grade | National percentile |
|---|---|---|
| Maricopa County | A | 86th |
| Coconino County | A | 86th |
| Apache County | A | 87th |
| Yavapai County | A | 88th |
| Greenlee County | A | 89th |
FAQ
How often does power go out in Pima County?
Between 2015 and 2025, Pima County recorded 1,722 outage events, averaging 2.0 hours each.
What is Pima County's reliability grade?
Pima County has a Reliability Grade of A, in the 86th national percentile.
What was the worst power outage in Pima County?
The worst outage on record started February 1, 2016 (Winter Storm), lasting 6 hours and affecting up to 55,764 customers.