Power outage history
Sangamon County Illinois
3.4hours
without power for the average customer in a typical year, 2018–2025
65th most of 101 in Illinois 49% below the national median
Every day since 2015
Eleven years, one night at a time
Each cell is a day. The brighter it is, the larger the share of Sangamon's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2023 was the worst well-recorded year, at 20 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Sangamon, hours without power per customer
The record
The biggest outages since 2015
Ranked by customer-hours lost: customers out multiplied by how long they stayed out. Times are local.
| Began | Storm | Peak out | Share | Lasted | 90% restored | Customer-hours |
|---|---|---|---|---|---|---|
| Jun 29, 2023 | Thunderstorms | 48,681 | 35% | 8.8 d | 6.0 d | 2.6M |
| Aug 12, 2021 | Thunderstorms | 12,454 | 9% | 7.2 h | 7.0 h | 46k |
| Mar 3, 2023 | Windstorm | 4,947 | 4% | 7.0 h | – | 24k |
| Feb 4, 2017 | No storm report | 2,865 | 2% | 9.0 h | – | 24k |
| Nov 29, 2025 | Winter storm | 3,083 | 2% | 7.8 h | – | 20k |
| Aug 12, 2016 | Flooding | 4,768 | 3% | 5.5 h | – | 17k |
| Nov 30, 2022 | No storm report | 3,469 | 3% | 4.8 h | – | 13k |
| Apr 4, 2024 | No storm report | 7,341 | 5% | 2.5 h | 1.8 h | 13k |
| Jun 20, 2015 | Tropical Storm Bill | 3,157 | 2% | 4.2 h | – | 12k |
| May 12, 2019 | No storm report | 2,816 | 2% | 3.5 h | – | 9.9k |
| May 20, 2019 | No storm report | 2,466 | 2% | 3.8 h | – | 9.2k |
| Mar 24, 2017 | No storm report | 2,253 | 2% | 4.0 h | – | 9.0k |
| Jan 5, 2016 | No storm report | 2,920 | 2% | 3.5 h | – | 8.7k |
| Apr 30, 2016 | No storm report | 2,390 | 2% | 3.5 h | – | 8.3k |
| Sep 21, 2025 | No storm report | 3,078 | 2% | 2.8 h | – | 7.7k |
| Jul 30, 2024 | Thunderstorms | 4,711 | 3% | 2.5 h | – | 7.3k |
| Dec 11, 2021 | Thunderstorms | 1,878 | 1% | 4.0 h | – | 7.0k |
| Jun 25, 2024 | Thunderstorms | 3,541 | 3% | 4.2 h | – | 6.8k |
| Mar 4, 2025 | No storm report | 3,522 | 3% | 2.0 h | – | 6.4k |
| Nov 25, 2018 | No storm report | 3,138 | 2% | 2.0 h | – | 6.2k |
| Feb 24, 2016 | No storm report | 2,699 | 2% | 2.5 h | – | 5.9k |
| Apr 1, 2016 | No storm report | 2,446 | 2% | 2.5 h | – | 5.9k |
| Jun 26, 2021 | Thunderstorms | 2,086 | 2% | 3.0 h | – | 5.5k |
| Dec 17, 2016 | Winter storm | 3,145 | 2% | 1.8 h | – | 5.3k |
| Dec 1, 2023 | No storm report | 1,674 | 1% | 3.0 h | – | 5.0k |
| Jul 21, 2020 | Thunderstorms | 1,919 | 1% | 4.0 h | – | 4.9k |
| May 16, 2025 | Thunderstorms | 4,076 | 3% | 2.2 h | – | 4.9k |
| Dec 26, 2021 | No storm report | 3,024 | 2% | 2.0 h | – | 4.7k |
| May 27, 2018 | Thunderstorms | 2,356 | 2% | 2.0 h | – | 4.6k |
| Jul 13, 2016 | Thunderstorms | 2,986 | 2% | 2.0 h | – | 4.5k |
After the peak
How fast the lights come back
Each line is one major outage, from its peak. The amber line is the typical path.
When it happens
The outage clock
Customer-hours out by month (rings, January innermost) and local hour, 2018–2025.
What was happening
Weather behind the outages
Each outage is matched to NOAA storm reports for Sangamon from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- Thunderstorms 93%
- No storm on record 5.0%
- Windstorm 0.9%
- Winter storm 0.8%
Who keeps the lights on
Utilities serving Sangamon
As each utility reports to the Energy Information Administration for its whole Illinois territory, not this county alone. Outage minutes include major storm days.
| Utility | Type | Outage min / yr | Excl. major storms | Outages / yr | Residential ¢/kWh | Customers |
|---|---|---|---|---|---|---|
| Ameren Illinois Company | Investor Owned | 287 | 130 | 1.19 | 16.7 | 1.1M |
| Rural Electric Conven Coop | IL | 142 | 87 | 1.56 | 13.0 | 87k |
| City of Springfield | Municipal | 71 | 71 | 0.79 | 13.1 | 59k |
| Village of Chatham | IL | – | – | – | – | 59k |
| Village of Riverton | IL | – | – | – | – | 25k |
| Shelby Electric Coop, Inc | Cooperative | – | – | – | 21.5 | 9.9k |
| Menard Electric Coop | Cooperative | 186 | 161 | 2.27 | 19.4 | 9.0k |
EIA Form 861, latest year each utility reported. Outage minutes are SAIDI, the yearly minutes the average customer goes without power; outages a year are SAIFI.
Next door
Neighbouring counties
About these numbers
Notes
Outages come from the EAGLE-I record of utility outage maps collected every 15 minutes by Oak Ridge National Laboratory. Hours without power are customer-hours divided by the county's 138,475 electricity customers. Averages use well-covered years from 2018. Outages shorter than 15 minutes, and utilities that publish no outage map, are not in the record, so these figures understate the total. How every number is made →