Power Out Map
– 0% of Grundy out 0 customers out in Illinois

Power outage history

Grundy County Illinois

2.3hours

without power for the average customer in a typical year, 2018–2025

82nd most of 101 in Illinois 65% below the national median

Worst outage on record Aug 11, 2020 9% of customers out · 90% back in 2.0 days
Hours without power, average customer per year 2.3h / yr State average 2.9 h · national median 6.6 h
Major outages a year 0.5 Peaks over 10% of customers or 50,000 customers
Typical time to restore 90% 12hours Median across major outages, from the peak
Longest single outage 3.8days Aug 10, 2020, over 1% of customers out
Outage hours on storm days 86% Share falling on days with a NOAA storm report here
Worst year 2020 6.1 hours without power, average customer
Electricity customers 43,433 ORNL customer model · 8 well-covered years

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 Grundy's customers who were without power at that day's worst moment.

20152016201720182019202020212022202320242025
0%100% of customers out

Year by year

Hours in the dark, per customer

2020 was the worst well-recorded year, at 6.1 hours for the average customer. Hatched years have a thin record and are left out of the averages.

Grundy, hours without power per customer

GrundyUS median countyIllinois average
0 2 4 6 8 3.7 ’15 0.4 ’16 0.8 ’17 1.6 ’18 1.6 ’19 6.1 ’20 1.9 ’21 0.5 ’22 1.1 ’23 4.7 ’24 1.1 ’25 US 6.6 IL 2.9

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
Aug 10, 2020 Thunderstorms 3,817 9% 3.8 d 2.0 d 207k
Jul 15, 2024 Thunderstorms 7,748 18% 43 h 25 h 176k
Jun 23, 2015 No storm report 2,831 7% 2.2 d 2.1 d 65k
Jun 22, 2015 Tornadoes 6,911 16% 5.8 h 14 h 28k
Sep 7, 2021 Thunderstorms 5,173 12% 13 h 9.5 h 27k
Jul 28, 2023 Thunderstorms 3,146 7% 19 h 20 h 24k
Jun 25, 2021 No storm report 7,310 17% 8.0 h 7.8 h 19k
Nov 26, 2018 No storm report 959 2% 20 h – 14k
May 15, 2025 Thunderstorms 1,244 3% 15 h – 14k
Jun 26, 2020 Thunderstorms 1,843 4% 13 h – 13k
Jun 30, 2019 Thunderstorms 1,306 3% 11 h – 11k
Sep 27, 2019 Flooding 3,164 7% 6.2 h 7.8 h 11k

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.

0% 25% 50% 75% 100% peak+24h+48h+72h+96h half back by +4h 90% by +10h

When it happens

The outage clock

Customer-hours out by month (rings, January innermost) and local hour, 2018–2025.

00061218 Jan inside

What was happening

Weather behind the outages

Each outage is matched to NOAA storm reports for Grundy from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.

  • Thunderstorms 82%
  • No storm on record 14%
  • Flooding 2.1%
  • Winter storm 0.9%

Who keeps the lights on

Utilities serving Grundy

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
Commonwealth Edison Co Investor Owned 77 38 0.66 17.7 3.8M

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

Across Illinois

Where it is darkest

Hours / yr64+

All Illinois 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 43,433 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 →