NEW YORK: US natural gas futures held near a 31-month high on Thursday ahead of a report expected to show last week's storage build was smaller-than-usual because power generators burned lots of the fuel to keep air conditioners humming during hot weather.

Analysts forecast US utilities added 21 billion cubic feet (bcf) of gas into storage during the week ended July 30. That compares with an increase of 32 bcf in the same week last year and a five-year (2016-2020) average increase of 30 bcf.

If correct, last week's injection would boost stockpiles to 2.735 trillion cubic feet (tcf), or 6.1% below the five-year average of 2.912 tcf for this time of year.

Front-month gas futures fell 1.4 cents, or 0.3%, to $4.144 per million British thermal units (mmBtu) at 7:36 a.m. EDT (1136 GMT). On Wednesday, the contract closed at its highest since December 2018.

Data provider Refinitiv said gas output in the US Lower 48 states rose to 91.7 billion cubic feet per day (bcfd) so far in August from 91.6 bcfd in July. That was still well below the all-time high of 95.4 bcfd in November 2019. Refinitiv projected average gas demand, including exports, would rise from 90.9 bcfd this week to 94.3 bcfd next week as power generators burn more fuel to meet rising air conditioning use.