New York economists are anxiously awaiting the release of new local employment figures, due out later this week, to see whether the city is defying national trends and staving off an economic downturn.

With Friday’s news that the nation shed 4,000 jobs between July and August, followed by Mayor Bloomberg’s memo to all city agency heads to tighten their fiscal belts, those monitoring the economy here say the next batch of economic indicators will be a crucial barometer of the city’s fiscal health.

“People are going to be watching the unemployment numbers, they are going to be watching some of the tax numbers, including the business income taxes that are due later this month, to get a better gauge on whether the city is starting to feel more of the effects of the national slowdown,” a spokesman for the Independent Budget Office, Douglas Turetsky, said.

Until now the city’s real estate market and overall economy has remained relatively strong. But, with Wall Street nose-diving and last week’s job loss figures, there is a feeling that New York, particularly the heavily relied-on financial services sector, may feel some pain soon. Mr. Bloomberg has been saying for months that the economic party is going to have to come to an end at some point.

The state Department of Labor is scheduled to release unemployment and job growth numbers on Thursday. Those numbers could shed some light on the strength or fragility of the economy here.

Yesterday, when asked how the national economic problems would affect New York, Senator Schumer said: “With the economy turning downward, it’s something we have to watch very carefully.” For the last 12-month period on record, which ended in May, private sector employment in New York City jumped 1.7%, with 52,000 new jobs. According to the state Labor Department, the professional and business service industry led the way with 13,800 jobs, followed by the educational and health services with 13,700 and finance with 11,900.

That was despite a city unemployment rate that inched up to 5.7% in July from its all-time low of 4.3% a few months ago. Mr. Bloomberg touted the 4.3% figure, saying it was a sign that efforts to create new jobs was working. And while, it might appear that the increase is a sign of a softening city job market, economists say the number probably went up because more New Yorkers entered the workforce to look for jobs and were captured in the figures.

The research director for the Citizens Budget Commission, Charles Brecher, said that while he is not expecting this week’s numbers to show declines, “everyone is waiting for the first shoe to drop” on New York’s economy. Mr. Brecher said rather than the unemployment rate, he’ll be looking for private sector employment, job growth, the employment ratios, and the number of jobs in the so-called FIRE industries of Finance, Insurance, and Real Estate.

“I wouldn’t say I’m expecting negative numbers, but I expect that at some point, in whatever it is, the next six to 18 months, we’ll probably see some dip,” Mr. Brecher said.

In his one-page memo to city agency heads on Friday, Mr. Bloomberg said the downturn in the financial markets will mean less money coming into the city’s bank account in the form of tax revenues.

“We recognize we have enjoyed a period of extraordinary economic growth and that the good times do not last forever,” he wrote. He told city commissioners only “critically necessary” hires should be made.

The city had a surplus of more than $4 billion for the most recent fiscal year but is predicting budget shortfalls for the future. Mr. Bloomberg said any changes in the city’s financial outlook will be made in its budget modification in November.

The president of the Partnership for New York City, Kathryn Wylde, said as long as the city’s housing market stays strong, it would be buffered to a certain extent.

“I don’t think we’re going to see a big impact in the short term,” she said. “The weakness in the housing market is the major factor in the national private sector job decline, and I don’t think we are going to see that reflected in the city and state numbers.”

If the nation plunges into a recession New York will eventually feel it, Ms. Wylde said. But she noted that the private sector has been creating jobs.

A report released late last month by the federal Bureau of Labor Statistics found that New York City had added more than 200,000 jobs over the last four years and that its job count was 0.2% below its July 2000 peak.