Power Out Map
– 0% of Jefferson out 0 customers out in Wisconsin

Power outage history

Jefferson County Wisconsin

5.5hours

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

18th most of 72 in Wisconsin 16% below the national median

Worst outage on record Jul 29, 2023 37% of customers out · 90% back in 44 hours
Hours without power, average customer per year 5.5h / yr State average 3.5 h · national median 6.6 h
Major outages a year 3.3 Peaks over 10% of customers or 50,000 customers
Typical time to restore 90% 4hours Median across major outages, from the peak
Longest single outage 2.6days Jul 28, 2023, over 1% of customers out
Outage hours on storm days 71% Share falling on days with a NOAA storm report here
Worst year 2023 16 hours without power, average customer
Electricity customers 34,512 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 Jefferson'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

2023 was the worst well-recorded year, at 16 hours for the average customer. Hatched years have a thin record and are left out of the averages.

Jefferson, hours without power per customer

JeffersonUS median countyWisconsin average
0 5 10 15 20 2.0 ’15 1.4 ’16 2.9 ’17 3.1 ’18 3.4 ’19 1.8 ’20 5.7 ’21 4.7 ’22 16 ’23 4.3 ’24 5.4 ’25 US 6.6 WI 3.5

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
Jul 28, 2023 Thunderstorms 12,904 37% 2.6 d 44 h 435k
Jul 29, 2021 Tornadoes 6,941 20% 22 h 15 h 66k
Jun 25, 2023 Windstorm 8,279 24% 13 h 5.2 h 50k
Dec 15, 2021 Windstorm 3,752 11% 21 h 18 h 47k
Jun 15, 2022 Thunderstorms 8,397 24% 11 h 6.2 h 42k
Jun 13, 2022 Thunderstorms 4,775 14% 23 h 12 h 35k
Jun 21, 2025 Heat 4,678 14% 14 h 9.2 h 35k
Jun 30, 2019 Thunderstorms 5,853 17% 8.2 h 6.0 h 33k
Aug 2, 2015 No storm report 5,251 15% 10 h 5.0 h 32k
Mar 15, 2025 Thunderstorms 7,953 23% 13 h 4.5 h 30k
Jun 27, 2019 Thunderstorms 4,142 12% 11 h 9.8 h 28k
May 17, 2017 Thunderstorms 2,348 7% 19 h 18 h 27k

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 +6h 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 Jefferson from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.

  • Thunderstorms 49%
  • No storm on record 29%
  • Windstorm 7.2%
  • Tornadoes 7.1%
  • Heat 2.8%
  • Winter storm 2.5%
  • Flooding 2.1%

Who keeps the lights on

Utilities serving Jefferson

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

Utility Type Outage min / yr Excl. major storms Outages / yr Residential ¢/kWh Customers
Wisconsin Electric Power Co Investor Owned 185 93 0.90 20.5 1.1M
Wisconsin Power & Light Co Investor Owned 96 75 0.79 18.5 441k
Adams-Columbia Electric Coop Cooperative 108 66 0.87 19.0 36k
Lake Mills Light & Water Municipal – – – 14.5 4.1k
Jefferson Utilities Municipal – – – 12.4 3.8k
Waterloo Light & Water Comm Municipal – – – 14.7 1.6k

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 Wisconsin

Where it is darkest

Hours / yr64+

All Wisconsin 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 34,512 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 →