Bitcoin mining difficulty jumps 15%, posting record absolute increase as hashrate rebounds after US winter storm

Bitcoin mining difficulty climbed 14.7% to 144.4 trillion in its latest adjustment on Friday, marking the largest absolute increase recorded as network hashrate rebounded following widespread curtailments during a recent U.S. winter storm.

The difficulty adjustment came at block height 937,440, according to data from the Bitcoin network explorer Mempool, erasing the prior epoch's sharp 11% decline. 

Bitcoin mining difficulty is not expressed in specific units. It is a relative measure of how hard it is to mine a new block compared to the easiest it could ever be. The difficulty automatically adjusts every 2016 blocks — roughly two weeks — to ensure that, on average, a new block is found every 10 minutes, regardless of how many miners are actively mining.

According to data from Clark Moody's dashboard, blocks were being produced at an average pace of 8 minutes and 47 seconds during the most recent epoch, significantly faster than the protocol's 10-minute target, prompting the upward adjustment. The network's hashrate rose from approximately 884 exahashes per second to 1,030 exahashes per second over the same period, per Mempool data, reflecting a substantial increase in active mining capacity.

Hashrate refers to the amount of computing power dedicated to securing the Bitcoin network and processing transactions. As miners reconnect equipment and hashrate rises, blocks are produced more quickly, prompting the network's automated adjustment to increase mining difficulty and restore the protocol's block production target.

The difficulty increase amounted to an absolute gain of roughly 18.5 trillion, surpassing all prior adjustments in raw terms. For context, the bitcoin network took over 11 years to reach 15T difficulty in total.

US winter storm impact

The latest adjustment follows a period of severe weather disruption across the United States, when a sweeping winter storm saw many operators temporarily power down equipment to reduce strain on electricity grids. At the time, an estimated 200 EH/s of computing power went offline across major mining pools, including a roughly 60% decline in hashrate connected to Foundry USA, the largest mining pool by market share. The decline pushed average block production times above 12 minutes and led to a significant downward adjustment in difficulty.

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The pullback reflected a growing pattern in which bitcoin miners act as flexible, interruptible loads during periods of extreme weather. Many large-scale mining operations participate in demand-response programs, allowing them to rapidly shut down rigs, sell power back to the grid, or avoid operating during peak pricing periods — receiving compensation or energy credits in return — to stabilize the electricity system.

With weather conditions easing, miners have since brought machines back online, restoring hashrate and reversing the slowdown in block production. Market participants attributed the recent surge in difficulty to this recovery rather than structural changes in mining economics. 

Historic difficulty swings

While the 14.7% increase ranks among the larger modern-era adjustments, it remains well below the largest percentage increases recorded in bitcoin's early years. The biggest upward adjustment in percentage terms occurred on July 9, 2011, when difficulty surged 31.5%, followed by a 29.9% increase on June 12, 2011, and a 23.2% rise on August 17, 2011, though the network was far smaller and hashrate growth was more volatile back then.

Despite marking the largest absolute increase recorded, the latest adjustment is still below the network's prior peak above 155 trillion reached in November 2025, per Mempool's data.