Neon signs were turned off, lights dimmed and thermostats dialed down in Japan on Tuesday after the government issued an urgent call to save energy, warning of blackouts after an earthquake last week caused a serious power shortage.

As snow fell in Tokyo and the temperature dropped to 2 Celsius (35.6 Fahrenheit), Tokyo Electric Power Co. Holdings Inc. (Tepco) said demand had spiked and up to 3 million households could lose power after 8 p.m. if usage rates did not come down.

The Ministry of Economy, Trade and Industry (METI) said later in the evening that the country was likely to avoid blackouts.