U.S. natural gas prices have already more than doubled since the beginning of the year and they could jump 25% or more this summer, according to CNBC.

Warmer weather and concerns over tight supplies have pushed futures prices higher. Last week, natural gas futures for June settled at $8.30 per million British thermal units, marking a 123% increase for the year.

These higher natural gas prices are putting even more pressure on U.S. consumers as gasoline and diesel fuel are at record levels. Furthermore, utilities that normally switch to coal for power when natural gas prices jump, dramatically, are discovering coal is even more costly.

Learn more: CNBC > Natural gas prices have already doubled this year. A hot summer could push them even higher