US EnergyData

System Average Interruption Duration Index (SAIDI) measures the average amount of time — in minutes — that an electricity customer experiences outages. This is shown with and without major events — mostly severe weather — included.
Data source: U.S. Energy Information Administration, Form EIA-861 Annual Electric Power Industry Report
Note: Values for states are calculated as the customer-weighted averages of utility-level SAIDI. Data covers distribution-level outages only.

What this data measures

SAIDI (System Average Interruption Duration Index) by state, showing both the figure excluding major event days and the figure including major event days side by side. The gap between the two lines shows how much major storms and extreme weather events contribute to outage duration in each state.

How this data is constructed

SAIDI data are reported by electric distribution utilities through the EIA Form EIA-861 Reliability Supplement. Utilities report both measures: "excluding major event days" uses the IEEE 1366 standard threshold to filter extreme events; "including major event days" is the raw total.

Source
U.S. Energy Information Administration, Form EIA-861 Reliability Supplement
Date range
2013–2024
Unit
Minutes of interruption per customer per year (customer-minutes)
Last updated
Fall 2025
Next update
Annual — expected fall 2026