Power outage knocks U.S. official time off by microseconds
A destructive windstorm-induced power outage at the National Institute of Standards and Technology’s Boulder, Colorado lab on Wednesday, followed by a failed backup generator, caused the U.S. official time standard (NIST UTC) to run 4.8 microseconds slow, agency officials said. Although the lab’s 16 atomic clocks continued operating on battery backup, the failure of connections to NIST’s measurement and distribution systems produced the drift, which could matter for high‑precision applications in telecommunications, GPS and critical infrastructure even as it remains imperceptible to the public; NIST staff later restored backup power with a reserve diesel generator and are now working to correct the error after main power was restored by Saturday evening.
📌 Key Facts
- NIST UTC, the official U.S. time standard, was 4.8 microseconds slower than intended after a Boulder, Colorado power outage and generator failure.
- The outage followed a destructive windstorm Wednesday at NIST’s Boulder campus; all 16 atomic clocks kept running on battery backups, but some lost connection to measurement and distribution systems.
- NIST officials say the drift is negligible for most people but potentially significant for high‑end users such as critical infrastructure, telecom and GPS; power was restored by Saturday evening and work is underway to realign the time signal.
📊 Relevant Data
Many components of the U.S. electric grid date back 40 to 70 years, well beyond their intended lifespan, increasing vulnerability to extreme weather events like windstorms.
Aging Electric Infrastructure in the United States — InterPro - University of Wisconsin
In 2024, the average Xcel Energy customer in Colorado experienced 350 minutes without electricity, nearly double the trend of 166 minutes from 2015 to 2023, due to increased outages.
Xcel Energy-Colorado power outages doubled in 2024 — The Denver Post
Lower income and racial-ethnic minority households in the US are more likely to experience a higher frequency and duration of power outages.
Shedding Light on Inequities of Power Outages Through Data — IOPscience
Minority communities in the US experienced disproportionately higher impacts from power outages compared to predominantly White communities, based on analysis from 2017 to 2020.
Analyzing structural inequalities in natural hazard-induced power outages — ScienceDirect
A December 2025 windstorm in Colorado caused power outages affecting over 150,000 customers, with wind gusts over 100 mph leading to widespread damage.
Winds tear across Front Range, causing widespread outages, closures — The Denver Post