As record high temperatures stifle the U.S., natural gas exchange traded funds may finally break out of their rut on increasing electricity needs.

The first five months of the year have been the hottest on record across the contiguous U.S., reports Douglas Main for LiveScience. According to the National Oceanic and Atmospheric Administration, over 40,000 daily heat records have been broken year-to-date. In June, 164 all-time high temperature records were tied or broken.

Jake Crouch, a climate scientist with National Climatic Data Center, noted that this is quite unusual, given that the summer heat typically turns up over July and August.

The rising temperatures may also be a new trend. For instance, over the last few years, daily record high temperatures have been outpacing daily record lows by two to one on average, according to Climate Central.

“This could be a harbinger of things to come,” Jeff Weber, a scientist with the University Corporation for Atmospheric Research, said in the article.

Meanwhile, the U.S. Natural Gas Fund (NYSEArca: UNG) has jumped almost 20% over the past three months as natural gas spot prices rallied from below $2 per million British thermal units. [Natural Gas ETF Buying Points to Bullish Accumulation]

Natural gas futures were trading at about $2.90 Thursday.