Bitcoin's network hashrate, a critical measure of computational power and security, experienced a dramatic collapse over the weekend of January 26-27, 2026, plummeting by approximately 40% from 1.133 zettahashes per second (ZH/s) to a seven-month low of 690 exahashes per second (EH/s). The primary cause was a severe winter storm and ice event across the United States, which forced major mining operations, particularly in Texas, to power down their equipment to relieve stress on the electrical grid.
The impact was concentrated in the United States, which accounts for roughly one-third of the global Bitcoin hashrate. Major publicly traded miners saw their daily Bitcoin production crash. Marathon Digital (MARA) saw its output fall from an average of 45 BTC to just 7 BTC, while CleanSpark dropped to 12 BTC, Iris Energy to 6 BTC, and Riot Platforms to just 3 BTC per day. The Foundry USA mining pool alone lost about 200 EH/s, representing a 60% decline in its hashrate.
The extreme cold led to skyrocketing electricity costs and prompted grid operators to issue emergency conservation alerts. Miners participated in demand-response programs, voluntarily shutting down to stabilize the grid, a move highlighted by Bitcoin ESG researcher Daniel Batten. The strain was so significant that Abundant Mines estimated 40% of the world's mining capacity was temporarily offline.
Concurrently, Bitcoin's mining difficulty adjusted downward by 4.54% to around 141.67 trillion, marking the first negative adjustment since September 2024. This drop, which began a consistent decline in November 2025, is primarily driven by miner unprofitability as BTC prices fell from 2025 highs near $126,000 while operational costs remained elevated. The reduced difficulty increases profitability for miners who remain online, as they face less competition for block rewards.
The network stress caused block times to increase to around 12 minutes, creating perceptible delays. Analysts warn that prolonged miner capitulation could add selling pressure to the market, as unprofitable operations may sell BTC holdings to cover fixed costs. At the time of reporting, BTC price traded around $87,856, showing slight daily gains but weekly losses. The event has sparked discussions within the industry about the risks of geographic concentration of mining and the need for greater infrastructure diversification and renewable energy procurement to mitigate future vulnerabilities.
