Dec 17 (Reuters) - Power prices in New England jumped on Friday to their highest levels since the winter of 2017-2018 on forecasts that homes and businesses will crank up their heaters next week to escape the first cold snap to hit the six-state region this winter. High temperatures in Boston will drop from 58 degrees Fahrenheit (14 Celsius) on Friday to 34 on Monday, according to AccuWeather. That compares with a normal high of 40 at this time of year. Next-day power prices in New England spiked from $35 for Friday to $228 per megawatt-hour (MWh) for Monday, the highest since January 2018. That compares with an average of $51 per MWh so far this year, $26 in 2020, when the coronavirus pandemic depressed demand, and a five-year (2016-2020) average of $37. High winter prices are nothing new for New England, where the limited number of pipelines regularly become constrained on the coldest days. But this winter could be worse. read more On the coldest days, most gas flowing into New England is used to heat homes and businesses so many gas-fired power plants, which usually supply about 55% of electricity generated in the region, must switch to other more expensive fuels like oil and liquefied natural gas (LNG). This year, LNG , is trading at record highs around the world that are 11 times more expensive than gas in the United States, and oil costs almost twice as much as it did this time last year. Looking ahead, gas at the Algonquin hub in New England was trading at more the $23 per million British thermal units (mmBtu) for January delivery, which would be the highest price paid for the fuel in a month since January 2014. That compares with an average of $4.28 per mmBtu so far this year, $1.97 in 2020 and a five-year average of $3.39.