US natural gas futures inched up on Thursday after a federal report showed a weekly storage build that was in line with estimates, but expectations for reduced cooling demand over the next weeks amid record production weighed.

Front-month gas futures for September delivery were up 0.9 cents, or 0.4%, at $2.18 per million British thermal units as of 11:06 a.m. EDT (1506 GMT).

The US Energy Information Administration (EIA) said utilities added 59 billion cubic feet (bcf) of gas into storage during the week ended Aug. 16.

That was mostly in line with a 60 bcf build that analysts forecast in a Reuters poll and compares with a five-year (2014-18) average build of 51 bcf for the period.

The increase last week boosted stockpiles to 2.797 trillion cubic feet (tcf), 3.6% below the five-year average, but still 15.2% above the same week a year ago.

The amount of gas in inventory has remained below the five-year average since September 2017. It fell as low as 33% below that average in March 2019. But with production expected to keep growing, analysts said, stockpiles should reach a near-normal 3.7 trillion cubic feet (tcf) by the end of the summer injection season on Oct. 31.

Meanwhile, Refinitiv data indicated 163 cooling degree days (CDDs) in the Lower 48 states over the next two weeks, below the 178 forecast on Tuesday. The normal is 166 CDDs for this time of year.

CDDs measure the number of degrees a day's average temperature is above 65 degrees Fahrenheit (18 degrees Celsius) and are used to estimate demand to cool homes and businesses.

"Production picked up and demand estimates are expected to fall in the next two weeks as we approach more fall-like weather ... Supply demand balance should be loosening in the next two weeks," said Robert DiDona of Energy Ventures Analysis.

Gas production in the Lower 48 US states rose to 91.9 bcfd on Wednesday from 91.2 bcfd on Tuesday, Refinitiv data showed, close to the all-time high of 92.5 bcfd scaled on Monday.

Analysts said gas futures had traded near multi-year lows since May because record output and mild spring weather allowed utilities to inject huge amounts of gas into storage.

With summer season approaching its end, Refinitiv data projected demand in the Lower 48 would fall to 88.2 bcfd next week from 91.8 bcfd this week. This compares with the 90.3 bcfd forecast the prior week.