Jenny Offill’s irresistible new novel ‘Weather’ is tiny in size and immense in scope.

Jenny Offill’s experimental 2014 novel, “Department of Speculation,” catapulted her from relative obscurity to the rarefied world of fame and acclaim. Named one of the top 10 books of the year by the New York Times Book Review, nominated for numerous awards, a national bestseller, “Speculation” was a most improbable, and delightful, of literary success stories. Offill’s new novel, “Weather,” is similarly tiny in size and immense in scope, radically disorienting yet reassuringly humane, strikingly eccentric and completely irresistible.

Offill’s novels are slim and spare, told in bursts and fragments and bits. They lack conventional structures, traditional suspense or straightforward characterization. Their narrative style is casual and seemingly incidental. They are comprised of everything from jokes to excerpts from other books to random observations about the subway, people’s clothing, and the weather.

“Weather” is deployed in the full panoply of its literal and figurative meanings here. Trump’s election signals an ominous change in the weather. Climate change looms large as an enormous source of anxiety. Clouds of worry, fear, and pessimism flit across the character’s minds. Sudden storms and tempests large and small upend their sense of self, threaten to destroy their relationships, destabilize them. In the midst of this tumult, there is also the unexpected sunlight of empathy, connection, and tenderness.

“Weather” is narrated by Lizzie, a middle-aged New York City librarian who dropped out of graduate school with half a completed dissertation in order to care for her drug-addicted brother, Henry. Her former academic mentor, Sylvia, pulled strings to get Lizzie the library position even though she lacked the proper credentials. Through her job and her apartment building, Lizzie engages with a host of colorful characters: “cranky professors” — from a recovering alcoholic with tenure to a “doomed adjunct” who sells his plasma to pay the bills — from the drug-dealer in Apt 5C to the New York Times-loathing and hate-mongering Mrs. Kovinski , from homeless people to a kindly car service driver whose business she may be single-handedly keeping afloat. “Regular life [has] become more fragmented and bewildering” for all of them.

Used as an expert, a confessor, a “fake shrink” by her patrons, her neighbors, and her family members, Lizzie is used to doling out advice, bolstering depressives, assuaging fear, solving problems. So when Sylvia, an expert on climate change who’s launched a podcast called “Hell and High Water,” asks her to take on the job of answering her e-mail, the position seems like a natural fit. Soon she is contending with an onslaught of letters, from left-wingers terrified about climate change to right-wingers certain the end of the world is near.

But if Lizzie is a competent and compassionate caretaker, she’s also anxious and struggling, oppressed and exhausted. Her “#1 fear is the acceleration of days”; parenting her young son, Eli, involves “trying to undo the rush” of his growing up in a culture of ambitious striving and a cutthroat educational system. She’s got a bum knee, an aging mother with infected and crumbling teeth whose generosity to the less fortunate exceeds her small “fixed income,” and a classicist husband who couldn’t get an academic job so ended up designing educational video games. Her brother has been doing better, but a hasty marriage to his pregnant girlfriend and the birth of their daughter have threatened his fragile equilibrium.

Offill’s characters turn to an array of coping strategies — some genuinely helpful and restorative, others counterproductive and addictive — for the dreariness and dread, anxiety and anguish that permeate their days. Lizzie binge-watches disaster movies and reality shows, Googles “prepper things” and makes plans for her doomstead, and reluctantly begins attending a meditation class. (Offill is brilliant on the allure and hypocrisies of commodified Buddhism.) Ben turns to the classical literature he once studied and takes to intricate woodworking. Henry attends 12-step meetings, plays video games, and relapses, getting high and cheating on his wife with an ex-girlfriend.

Eventually, Lizzie falls into an emotional affair with a sexy, free-spirited journalist named Will, who’s just back from Syria, “firmly in the school of whatever gets you through the night,” and a patient listener to her rants about “the coming chaos” and riffs on useful skills to survive the apocalypse. As she “blather[s] on about Zazen,” he offers her a naturally Zen outlook and rakish nonchalance that are increasingly rare in her turbulent and troubled world.

Lizzie is what we might call a co-dependent, or a hypochondriac, or a paranoid worrier. She’s chided for her “enmeshment” with her brother, and Ben grows increasingly weary as his wife tips into obsession. But she is also all of us; she embodies in exaggerated or extreme form the fears, consuming preoccupations, and anxieties that beset so many in this most uncertain and frightening of times. And her kindness, her generosity of spirit, her desire to help despite being uneasy with typical modes of activism endear her to us again and again.

A narrator and a novel that hum with anxiety and pulse with dread are nonetheless hilarious, warm, and lovable. Both ruefully mordant and strangely consoling, “Weather” is at once brutal in its unsparing honesty and utterly exhilarating in its wit and intelligence. It radiates with the beleaguered yet buoyant optimism, the luminous integrity, of a supple and fearless writer.

WEATHER

by Jenny Offill

Knopf, 224 pp. $23.95

Priscilla Gilman is a former professor of English literature at Yale University and Vassar College and the author of “The Anti-Romantic Child: A Memoir of Unexpected Joy.’’