Power Out Map
– 0% of Cobb out 0 customers out in Georgia

Power outage history

Cobb County Georgia

2.2hours

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

145th most of 156 in Georgia 67% below the national median

Worst outage on record Dec 9, 2017 21% of customers out · 90% back in 40 hours
Hours without power, average customer per year 2.2h / yr State average 6.7 h · national median 6.6 h
Major outages a year 0.1 Peaks over 10% of customers or 50,000 customers
Typical time to restore 90% 39hours Median across major outages, from the peak
Longest single outage 2.9days Dec 8, 2017, over 1% of customers out
Outage hours on storm days 73% Share falling on days with a NOAA storm report here
Worst year 2020 5.0 hours without power, average customer
Electricity customers 322,249 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 Cobb'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 5.0 hours for the average customer. Hatched years have a thin record and are left out of the averages.

Cobb, hours without power per customer

CobbUS median countyGeorgia average
0 2 4 6 8 10 0.7 ’15 1.2 ’16 7.8 ’17 1.2 ’18 1.0 ’19 5.0 ’20 0.9 ’21 1.6 ’22 2.3 ’23 2.7 ’24 2.7 ’25 GA 6.7 US 6.6

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
Dec 8, 2017 Winter storm 67,177 21% 2.9 d 40 h 2.0M
Oct 29, 2020 Hurricane Zeta 65,007 20% 2.4 d 39 h 1.2M
Feb 16, 2025 No storm report 22,023 7% 11 h 8.8 h 131k
Jun 7, 2025 Thunderstorms 27,607 9% 9.5 h 7.5 h 99k
Jun 25, 2023 Thunderstorms 22,843 7% 7.2 h 8.8 h 84k
Jul 30, 2024 No storm report 14,648 5% 7.8 h 11 h 57k
Sep 27, 2024 Hurricane Helene 9,186 3% 9.8 h 11 h 54k
Mar 21, 2017 Thunderstorms 11,044 3% 5.2 h 6.2 h 39k
Sep 11, 2017 Hurricane Irma 6,242 2% 8.5 h 20 h 37k
Dec 29, 2024 Tornadoes 8,074 3% 5.2 h 16 h 29k
Sep 7, 2022 No storm report 4,981 2% 7.2 h – 27k
Mar 15, 2025 No storm report 6,362 2% 5.8 h 9.0 h 26k

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 Cobb from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.

  • Tropical storm 58%
  • No storm on record 27%
  • Thunderstorms 12%
  • Tornadoes 2.2%
  • Windstorm 0.5%

Who keeps the lights on

Utilities serving Cobb

As each utility reports to the Energy Information Administration for its whole Georgia territory, not this county alone. Outage minutes include major storm days.

Utility Type Outage min / yr Excl. major storms Outages / yr Residential ¢/kWh Customers
Georgia Power Co Investor Owned 287 155 1.83 16.3 2.5M
Cobb Electric Membership Corp Cooperative 48 32 0.86 11.6 203k
GreyStone Power Corporation Cooperative 241 81 2.28 12.6 143k
City of Acworth GA – – – 15.2 63k
City of Marietta Municipal 106 106 1.30 11.9 36k

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 Georgia

Where it is darkest

Hours / yr64+

All Georgia 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 322,249 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 →