Bitcoin Mining Faces Weather Shock as Winter Storm Fernan Knocks Out Major Pools Across the US

Key Takeaways

• Winter Storm Fernan triggered widespread mining curtailments in the U.S., with Foundry USA taking roughly 200 EH/s offline.
• The sudden hashrate drop pushed Bitcoin block times closer to 12 minutes, briefly slowing network processing.
• Despite the disruption, Bitcoin’s price remained largely unaffected, continuing to trade in the $87,000–$89,000 range.

A powerful winter storm has offered a rare real-time stress test for Bitcoin’s U.S.-heavy mining industry.

As Winter Storm Fernan swept across large parts of the United States, bringing extreme cold, snow, ice, and freezing rain, power grids came under strain.

In response, major Bitcoin miners voluntarily shut down operations or were forced offline, triggering one of the sharpest short-term declines in U.S. hashrate in recent years.

Winter Storm Fernan Knocks Mining Offline

The most visible impact came from Foundry USA, one of the largest Bitcoin mining pools in the world.

As the storm intensified, Foundry’s hashrate fell by roughly 60% , with an estimated 200 exahashes per second (EH/s) taken offline.

At its lowest point, the pool’s hashrate dropped to about 198 EH/s, accounting for roughly 23% of the global mining network.

Other U.S.-linked mining pools reported similar pullbacks.

Combined, these shutdowns removed well over 100 EH/s from the network, with some estimates placing the total reduction as high as 30% during peak curtailment periods.

The outages were largely voluntary. Many Bitcoin miners participate in demand-response programs that compensate them for powering down during periods of extreme grid stress.

The approach mirrors past winter and summer curtailments, especially in states like Texas, where mining operations tie closely into local energy markets.

Hashrate Drops, Block Times Stretch

With fewer machines competing to secure the network, Bitcoin’s block production slowed.

Average block times drifted toward 12 minutes, up from the network’s long-term target of roughly 10 minutes.

The slowdown briefly reduced transaction throughput and extended confirmation times, though no major congestion was reported.

Because the shutdowns were expected and temporary, fee pressure remained contained.

Analysts note that short-term hashrate declines can slightly improve solo mining odds and reduce competition for remaining miners, though the effect is fleeting.

As power returns and temperatures stabilize, mining activity typically rebounds quickly, restoring normal network conditions ahead of the next difficulty adjustment.

A Reminder of Mining’s Weather Risk

Fernan’s impact highlights an ongoing vulnerability in Bitcoin’s mining geography.

As computing power increasingly concentrates in North America, extreme weather events are increasingly influencing short-term network performance.

The episode has reignited discussion around geographic diversification and energy sourcing.

This includes greater use of renewables and more globally distributed mining infrastructure to reduce regional risk.

Still, the network functioned as designed. Blocks continued to settle, transactions cleared, and miners responded flexibly to grid conditions, reinforcing Bitcoin’s resilience under stress.

Price Shrugs Off the Disruption

Despite the sharp drop in hashrate, Bitcoin’s price showed little direct reaction to the storm.

Over the weekend, BTC briefly dipped below $86,500 before recovering, extending a broader pullback that erased gains from earlier in the week when prices touched $97,000.

By the time mining operations began stabilizing, Bitcoin was trading back in the $87,000–$89,000 range.

Market participants largely attributed price movements to macro factors rather than mining disruptions, underscoring a familiar pattern: short-term operational shocks to the network rarely translate into immediate price volatility.

As miners power back up and Fernan fades, the episode is likely to be remembered less for its market impact and more as another demonstration of how closely Bitcoin mining has become tied to real-world infrastructure—and real-world weather.