St. Louis CountyPower Outage History
What this grade means
Bottom 20% least reliable nationally — frequent and/or long outages. This county ranks in the least reliable fifth of all US counties in our dataset: some combination of frequent outages, long restoration times, or customers affected puts it near the bottom nationally. Backup power is worth prioritizing here rather than treating it as optional.
Outages by year
Outages by month (seasonality)
Worst outage events on record
| Date | Duration | Customers affected | Cause |
|---|---|---|---|
| Jun 30, 2023 | 147 hrs | 83,685 (59%) | Thunderstorm Wind |
| Aug 12, 2021 | 75 hrs | 69,559 (49%) | Excessive Heat |
| Jul 29, 2023 | 54 hrs | 62,328 (44%) | Excessive Heat |
| Aug 10, 2020 | 66 hrs | 44,212 (31%) | Thunderstorm Wind |
| Jul 10, 2021 | 90 hrs | 40,765 (29%) | Thunderstorm Wind |
Was There an Outage on a Specific Date?
Pick a date to see whether a power outage was recorded for St. Louis County, Missouri that day.
Over the 12 years from 2014 to 2025, St. Louis County recorded 2,860 distinct power outage events, averaging 3.1 hours per event.
The single worst outage on record in St. Louis County started June 30, 2023 (Thunderstorm Wind), lasting 147 hours and leaving up to 83,685 customers without power (59% of the county) at its peak.
July has historically been the worst month for outages in St. Louis County, with 381 events recorded during that month across the dataset.
Based on this history, St. Louis County earns a Reliability Grade of F, placing it in the 10th percentile nationally for grid reliability (higher percentile = more reliable).
Similar counties in Missouri
Counties with the closest reliability grade and national percentile to St. Louis County.
| County | Grade | National percentile |
|---|---|---|
| Reynolds County | F | 20th |
| Iron County | D | 22nd |
| Lawrence County | D | 33rd |
| Bollinger County | D | 36th |
| Holt County | D | 38th |
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. Louis County?
Between 2014 and 2025, St. Louis County recorded 2,860 outage events, averaging 3.1 hours each.
What is St. Louis County's reliability grade?
St. Louis County has a Reliability Grade of F, in the 10th national percentile.
What was the worst power outage in St. Louis County?
The worst outage on record started June 30, 2023 (Thunderstorm Wind), lasting 147 hours and affecting up to 83,685 customers.