St. Clair CountyPower Outage History
What this grade means
Average — typical outage frequency and duration nationally. This county sits in the middle of the national distribution — its outage frequency and duration over the past 12 years are close to the nationwide median, neither notably better nor worse than most other US counties. A typical amount of backup-power preparedness is reasonable here.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Jul 13, 2016 | 55 hrs | 40,861 (27%) | Thunderstorm Wind |
| Jun 28, 2018 | 16 hrs | 28,750 (19%) | Flash Flood |
| Oct 25, 2021 | 14 hrs | 28,422 (19%) | Thunderstorm Wind |
| Mar 14, 2025 | 58 hrs | 18,062 (12%) | High Wind |
| Jun 29, 2018 | 9 hrs | 14,781 (10%) | Flash Flood |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for St. Clair County, Illinois that day.
Over the 12 years from 2014 to 2025, St. Clair County recorded 990 distinct power outage events, averaging 3.0 hours per event.
The single worst outage on record in St. Clair County started July 13, 2016 (Thunderstorm Wind), lasting 55 hours and leaving up to 40,861 customers without power (27% of the county) at its peak.
July has historically been the worst month for outages in St. Clair County, with 128 events recorded during that month across the dataset.
Based on this history, St. Clair County earns a Reliability Grade of C, placing it in the 58th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Illinois
Counties with the closest reliability grade and national percentile to St. Clair County.
| County | Grade | National percentile |
|---|---|---|
| Stephenson County | C | 57th |
| Marion County | C | 59th |
| Lawrence County | C | 60th |
| Woodford County | C | 60th |
| Alexander County | B | 60th |
Most reliable counties nationally
The top 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | South Dakota | A | 100th |
| Clearwater County | Minnesota | A | 99th |
| Limestone County | Alabama | A | 99th |
Least reliable counties nationally
The bottom 3 counties nationally by reliability grade and percentile.
| County | State | Grade | National percentile |
|---|---|---|---|
| Clay County | West Virginia | F | 0th |
| Lincoln County | West Virginia | F | 0th |
| Cameron Parish | Louisiana | F | 0th |
FAQ
How often does power go out in St. Clair County?
Between 2014 and 2025, St. Clair County recorded 990 outage events, averaging 3.0 hours each.
What is St. Clair County's reliability grade?
St. Clair County has a Reliability Grade of C, in the 58th national percentile.
What was the worst power outage in St. Clair County?
The worst outage on record started July 13, 2016 (Thunderstorm Wind), lasting 55 hours and affecting up to 40,861 customers.