NEW JERSEY (BLOOMBERG) - Governor Phil Murphy's administration asked people in New Jersey in the United States to use less water amid a heat spell and scarce statewide rainfall.

Some parts of New Jersey, including Newark, the state's most populous city, had recorded five straight days of temperatures 38 deg C or higher through Sunday (July 24).

For the past 90 days, rainfall is 11 per cent to 25 per cent below normal in most of the state's south and north, according to the National Weather Service.

"Now is the time for New Jersey to be especially mindful of water usage and pro-actively moderate our consumption," Mr Shawn LaTourette, the state environmental commissioner, said in a statement.

"Simple steps, like reducing lawn and landscape watering, go a long way in preserving our water supplies and avoiding the necessity of significant restrictive measures."

Officials stopped short of enacting restrictions. Though reservoir levels are adequate, the US Drought Monitor website lists northern and southern parts of the state as abnormally dry, as are parts of New York and Pennsylvania, according to the state environmental protection department.

That's a classification one step before moderate drought, which is affecting states including New Hampshire, Rhode Island, Maine and Massachusetts.

The tracker, run by the University of Nebraska-Lincoln and the federal government, can be an earlier indicator of dwindling supplies than reservoir levels alone, Gov Murphy's office said.