Rosh Hashana (New Year) begins at sundown Sept. 6 and Yom Kippur (the Day of Atonement) at sundown Sept. 15. Last year, both of the annual Jewish observances -- set by a lunar calendar -- fell shortly after the attacks.
"I expect every rabbi to devote at least one sermon to the whole problem of terror in the world," says Rabbi Doniel Kramer of the New York Board of Rabbis.
And the customary ritual prayers for this nation and for Israel will "resonate very powerfully" this year, says Rabbi Mark Diamond of the Board of Rabbis of Southern California.
Security was a priority for Jewish congregations even before the attacks though the Sept. 11 anniversary will increase vigilance during the holiday period.
Jews "have a different benchmark than 9-ll," says Jay Tcath of Chicago's Jewish Community Relations Council, but the attacks that day added "the exclamation point."
Tcath says that security became a priority among most American Jews in 1999. That year, a white supremacist on a Midwest shooting rampage killed two people and wounded nine; all the victims were Orthodox Jews, blacks or Asians. Weeks later, another racist sprayed the lobby of a Los Angeles Jewish community center with gunfire, killing one person and wounding five.
Observers also say Jewish alertness has increased with the Mideast suicide bombings, attacks on Jewish institutions in Europe and the June FBI warning that terrorists might use fuel tanker trucks to target Jewish synagogues or schools, as happened last May in Tunisia when 18 died.
One of the more dramatic reactions to the truck threat occurred this summer at New York City's Central Synagogue, which placed concrete barriers around its historic building.
"It's heartbreaking," says Central's Rabbi Peter Rubinstein, and "what makes it heartbreaking is the environment in which we and others have to do this."
Chicago's Jewish Federation installed barriers at its building after the Sept. 11 attacks, and spent nearly $1 million on security at affiliated agencies following the events of 1999, Tcath says.
Each year, Jewish organizations in several major cities have been holding security briefings for rabbis with police or FBI agents to prepare for the High Holy Days.
At this year's briefing in Miami, the mood was "not fearful, but prudent," says Judy Gilbert-Gould, director of that region's community relations council. Participants were advised, to "be vigilant, be secure before you need it."
Since late July, David Pollock of New York's Jewish Community Relations Council has sent 4,000 copies of a "Security Alert" brochure to Jewish institutions around the country, one of several such publications that are being provided this year.
Among its High Holy Day tips are to control entrances to synagogues and check the background of caterers, bakers, florists and janitorial service firms.
When it comes to the spiritual aspects of the holidays, preparation began months ago.
The annual High Holy Days seminar for Los Angeles area rabbis was titled "Faith and Fear: Spiritual Responses to Living with Terror." Diamond says that "rabbis want to help congregants deal with increased fear on a personal level."
The liberal Reform branch is distributing a special package of Sept. 11 materials that includes everything from modern poems to excerpts from President Roosevelt's 1941 "Four Freedoms" speech to a Muslim prayer for peace.
Orthodox and Conservative congregations are more restricted in liturgy, but can make use of appropriate readings from the Psalms and prayer books.
The New York Board of Rabbis, which covers all Jewish branches, has sent a suggested prayer for the Sept. 11 anniversary to all area synagogues.
It asks God to bless the United States, Israel, and their leaders; that "all who desire to live in peace may do so in safety" and that "the souls of all the innocent victims may be blessed and granted eternal rest."