Power outage history
Jefferson County Colorado
5.8hours
without power for the average customer in a typical year, 2018–2025
10th most of 39 in Colorado close to 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 Jefferson's customers who were without power at that day's worst moment.
Year by year
Hours in the dark, per customer
2025 was the worst well-recorded year, at 14 hours for the average customer. Hatched years have a thin record and are left out of the averages.
Jefferson, 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 |
|---|---|---|---|---|---|---|
| Apr 6, 2024 | Windstorm | 73,150 | 26% | 2.5 d | 36 h | 2.0M |
| Dec 19, 2025 | Windstorm | 51,319 | 18% | 2.7 d | 2.0 d | 1.7M |
| Dec 17, 2025 | Windstorm | 48,638 | 17% | 35 h | 11 h | 1.2M |
| May 20, 2022 | Winter storm | 57,450 | 21% | 46 h | 27 h | 895k |
| Mar 13, 2019 | No storm report | 33,384 | 12% | 2.2 d | 41 h | 575k |
| Dec 15, 2021 | Windstorm | 26,543 | 10% | 27 h | 22 h | 288k |
| Mar 14, 2024 | Winter storm | 24,922 | 9% | 37 h | 28 h | 250k |
| Jun 6, 2020 | Thunderstorms | 14,351 | 5% | 25 h | 29 h | 152k |
| Mar 23, 2016 | Winter storm | 13,179 | 5% | 19 h | 29 h | 132k |
| Dec 30, 2021 | Windstorm | 25,418 | 9% | 6.8 h | 3.5 h | 81k |
| Mar 31, 2023 | Windstorm | 17,102 | 6% | 6.8 h | 5.5 h | 63k |
| Oct 11, 2020 | Windstorm | 15,411 | 6% | 7.0 h | 5.2 h | 56k |
| Oct 9, 2017 | Winter storm | 7,248 | 3% | 10 h | 9.0 h | 54k |
| Apr 9, 2024 | No storm report | 6,116 | 2% | 13 h | 8.5 h | 45k |
| Mar 24, 2025 | Windstorm | 13,708 | 5% | 2.8 h | 2.8 h | 32k |
| Nov 8, 2024 | Winter storm | 6,543 | 2% | 8.2 h | 15 h | 31k |
| May 6, 2024 | Windstorm | 12,707 | 5% | 3.8 h | 8.0 h | 26k |
| Apr 17, 2018 | Windstorm | 5,899 | 2% | 6.0 h | 17 h | 26k |
| May 21, 2019 | No storm report | 5,303 | 2% | 6.0 h | 4.0 h | 25k |
| Jul 26, 2022 | No storm report | 8,501 | 3% | 4.5 h | 5.8 h | 24k |
| May 23, 2015 | No storm report | 12,136 | 4% | 6.0 h | 2.8 h | 23k |
| Apr 27, 2024 | Winter storm | 5,404 | 2% | 5.2 h | 12 h | 22k |
| May 18, 2017 | Winter storm | 4,405 | 2% | 7.2 h | – | 21k |
| Jul 25, 2024 | No storm report | 5,471 | 2% | 4.2 h | 1.5 h | 19k |
| Sep 21, 2023 | No storm report | 3,372 | 1% | 5.2 h | – | 18k |
| Sep 21, 2023 | No storm report | 9,819 | 4% | 2.0 h | 2.0 h | 17k |
| Apr 5, 2022 | Winter storm | 4,183 | 2% | 5.8 h | – | 17k |
| Mar 15, 2023 | No storm report | 7,850 | 3% | 2.8 h | 2.0 h | 17k |
| Aug 21, 2023 | No storm report | 13,916 | 5% | 1.8 h | 1.5 h | 17k |
| Mar 18, 2025 | No storm report | 3,605 | 1% | 4.2 h | – | 15k |
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 Jefferson from twelve hours before it began to its peak. Matching shows coincidence, not proof of cause.
- Windstorm 64%
- No storm on record 18%
- Winter storm 16%
- Thunderstorms 2.0%
Who keeps the lights on
Utilities serving Jefferson
As each utility reports to the Energy Information Administration for its whole Colorado territory, not this county alone. Outage minutes include major storm days.
| Utility | Type | Outage min / yr | Excl. major storms | Outages / yr | Residential ¢/kWh | Customers |
|---|---|---|---|---|---|---|
| Public Service Co of Colorado | Investor Owned | 360 | 149 | 1.58 | 15.9 | 1.4M |
| CORE Electric Cooperative | Cooperative | 381 | 52 | 0.97 | 15.6 | 169k |
| United Power, Inc | Cooperative | 303 | 90 | 1.18 | 16.5 | 103k |
| WAPA-- Western Area Power Administration | Federal | – | – | – | – | – |
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
- Clear Creek 31 h
- Park 23 h
- Gilpin 7.9 h
- Teller 5.9 h
- Jefferson (this county) 5.8 h
- Boulder 5.3 h
- Denver 3.0 h
- Adams 2.4 h
- Arapahoe 2.2 h
- Broomfield 1.8 h
- Douglas 1.2 h
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 278,207 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 →