Natural-gas futures fell Wednesday on some profit-taking ahead of a weekly inventory report while a heat wave supporting prices rolled toward the East Coast.

Natural gas for August delivery settled down 3.3 cents, or 0.7%, at $4.500 per million British thermal units on the New York Mercantile Exchange.

The benchmark contract almost reached $4.60 during the session, but fell as low as $4.433/MMBtu before paring some losses.

There was some pre-report profit-taking during the session as traders waited for data from the Energy Department, said Gene McGillian, an analyst with Tradition Energy.

The market was being cautious ahead of the report, he said, as the last two weeks have resulted in larger-than-expected injections of natural gas that triggered prices to fall.

In a Dow Jones Newswires survey, analysts and traders said they expect the Energy Information Administration to report that 62 billion cubic feet of gas was added to storage during the week ended July 15. That result would be above last year's 55-bcf storage build but below the five-year average injection of 67 bcf.

"We probably need an injection of less than 55 [bcf] to get to that $4.75 level," McGillian said.

Injections that are below predictions often lift prices, while those that exceed expectations typically push prices lower.

Futures have risen nearly 50 cents in the past two weeks due to strong seasonal factors.

An "increasing mix of short-term temperature forecasts" drove some of the market's volatility Wednesday, said Jim Ritterbusch, head of trading advisory firm Ritterbusch & Associates, in a client note.

Temperatures in the mid-Atlantic and Northeast are expected to surge into the upper 90s and low 100s from Thursday to Saturday, investment bank Macquarie said in a weekly report.

Heat and humidity in the Midwest have already pushed heat index levels above 100 degrees this week.

Demand for natural gas is likely to rise in the next few days as those in the eastern half of the country seek ways to cool off. The power-plant fuel is used to generate electricity to power air conditioning.

The EIA's natural-gas inventory report is scheduled to be released Thursday at 10:30 a.m. EDT.

   Nymex August        $4.500             -3.3c 
   Nymex September     $4.469             -4.2c 
   Nymex October       $4.483             -4.3c 
   CASH HUB            RANGE              PREVIOUS DAY 
   Henry Hub         $4.51-$4.655         $4.55-$4.62 
   Transco 65        $4.58-$4.685         $4.58-$4.62 
   Tex East M3       $4.98-$5.28          $4.98-$5.20 
   Transco Z6        $7.95-$10.10         $5.95-$7.25 
   SoCal             $4.54-$4.64          $4.47-$4.57 
   El Paso Perm      $4.46-$4.515         $4.35-$4.46 
   El Paso SJ        $4.34-$4.39          $4.285-$4.40 
   Waha              $4.545-$4.585        $4.49-$4.55 
   Katy              $4.51-$4.595         $4.48-$4.56