Josh Radnor and Jordana Jacobs were married outdoors this month, amid a snowstorm, with their 164 snow-drenched guests shivering in the 20-degree evening air, as Dr. Jacobs read a 10-minute monologue about her beloved, and Mr. Radnor responded with a 10-minute soliloquy.

No strangers to extraordinary circumstances, the couple fell for each other while tripping on mushrooms.

It was February 2022, and Dr. Jacobs, a clinical psychologist, and Mr. Radnor, an actor and musician, were at a sound meditation retreat held in upstate New York, along with about 30 other people. There, they ingested a psychedelic mixture before lying on the floor at opposite sides of a large room. Masks covered their eyes as they listened to singing bowls and chimes.

That is when Mr. Radnor and Dr. Jacobs slid into the DMs of each other’s consciousness.

“That’s her,” Mr. Radnor, now 49, said a voice told him. “That’s your woman.”

Across the room and the psilocybin-infused metaverse, Dr. Jacobs, 36, was having a conversation with her heart.

“What do you have to tell me?” she asked it.

“You know that man over there across the room, Josh?” it replied. “You’re drawn to him.”

They had met the previous day, at the onset of the three-day retreat, which was centered around the meditation “ceremony.”

Mr. Radnor, the star of the sitcom “How I Met Your Mother,” who more recently appeared in “Fleishman Is in Trouble” on Hulu, had been processing a painful breakup for a few months. He bounced from his house in Los Angeles to his parents’ place in Columbus, Ohio, to an Airbnb in Nashville, where he was recording an album with friends. Then he arrived in New York for a weekend of amplified self-evaluation.

Dr. Jacobs lives in Brooklyn, a subway ride from her close-knit family. She is a clinical psychologist with a private practice there. She graduated from Tufts University and received a doctorate of clinical psychology from Long Island University, Brooklyn.

She made the trip upstate that weekend as well because “these experiences have been very powerful for me in understanding who I am,” she said. She, too, was healing from a broken relationship and had decided that this weekend would signify a new, less cerebral orientation in which she would be guided by her heart.

The night before the meditation, she and Mr. Radnor chatted for half an hour. “We just fell into a really easy, fun kind of getting-to-know-you session,” he said.

They spoke of love and death, and the connection between them, which Dr. Jacobs told him she had studied. But she told him that she feared her approach was overly “academic and intellectual.”

“I need more experience with both,” she said. Mr. Radnor was intrigued. “I thought it was evidence of real depth,” he said. “I thought she was formidable.”

They discussed his songwriting, which also integrates themes of love and death, including in the album he was recording in Nashville, which he ultimately titled “Eulogy.” Dr. Jacobs felt a spark, too.

Every couple has a version of flirting. This was theirs.

After their psychedelic experience, as part of Dr. Jacobs’s new commitment to being guided by her emotions, she felt obligated to tell Mr. Radnor that she liked him.

She tapped him on the shoulder. “I had this experience in ceremony of listening to my heart,” she told him, sheepishly, “and my heart is drawn to you.”

Slightly panicked by the feelings stirring inside him, Mr. Radnor replied, “You came up for me in ceremony as well, but I’m not ready to talk about it.”

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Within minutes of leaving the retreat, he was ready. “Hi, it’s Josh Radnor,” he texted her.

This began a monthlong, modern-day epistolary courtship. They discussed their families — both of their parents have had long, successful marriages. She has brothers (three), he has sisters (two).

They talked about her career and his creative efforts to escape the shadow cast by a long-running hit sitcom. Dr. Jacobs, a television buff, said she had never seen “How I Met Your Mother,” which thrilled Mr. Radnor. “Fame robs you of an ability to make a first impression,” he said.

They talked, texted and sent voice memos. “We were constantly in touch, sharing things we had written and things we had made,” he said. “Thoughts, feelings, insights.”

Weeks later, Mr. Radnor was cast in “Fleishman Is in Trouble,” which was filming in New York. He sublet a friend’s apartment in Brooklyn and invited Dr. Jacobs to meet him for dinner.

“We had a really beautiful and intense and powerful first date where we went very deep,” she said.

Later that night, Mr. Radnor developed what he called a “vulnerability hangover” and told her “my walls had gone up,” he said.

Rather than feeling rejected, Dr. Jacobs was moved by his honesty. “To me, it showed me that he could process with me in the moment and tell me what was going on for him,” she said. “I just loved that.”

They grew inseparable. He officially moved from Los Angeles to Brooklyn. She became enamored with his labradoodle, Nelson the Dog. Within months, they were discussing marriage.

“Actors and shrinks,” said Gillian Sturtevant, Dr. Jacobs’s close friend from high school, explaining the couple’s compatible proclivity to talk (and talk) about their feelings.

They became engaged one morning in May in Joshua Tree, Calif. First, they meditated. Then Mr. Radnor casually suggested that they write each other love letters. His ended with a proposal.

Their friends view them as a perfect match. “They are in a perpetual ‘college-dorm-go-deep’ mode that most adults abandon after graduation,” said Elliott Holt, a fiction writer who attended Kenyon College in Gambier, Ohio, with Mr. Radnor.

The couple decided on a January wedding in New York, right before Mr. Radnor would start rehearsals for “The Ally,” a new play opening in February at the Public Theater.

They settled on a location: Cedar Lakes Estate, a former summer camp that was converted into an event space in Port Jervis, N.Y. The only available date that worked for the couple was the third anniversary of the attack on the U.S. Capitol. “We decided we would rebrand Jan. 6,” Mr. Radnor said.

Since their relationship started at a sound meditation ceremony, they planned for the wedding weekend to reflect the concept of “set and setting,” which, in the psychedelic context, refers to the interaction between one’s emotional and mental state and the physical environment.

The night before the wedding, there was a dinner with decorative mushrooms integrated into the centerpieces and at least one speech that referenced Sigmund Freud and Carl Jung. (There were seven therapists in attendance from just Dr. Jacobs’s family.) Guests wrote their intentions on cards and tossed them into a fire.

Mr. Radnor strummed his guitar — the only other sound was the crackle of burning wood — as he sang lyrics he wrote for his bride: “One day this’ll all be gone, what remains will be the songs I sang to you.”

On the morning of the wedding, there was yoga and then a (drugless) sound meditation. And then — in the couple’s most significant attempt to stimulate the senses — the ceremony was called to take place outside in the bracing cold at dusk.

Not even a snowstorm, which had been predicted by meteorologists for days, could thwart the couple’s intentions. So their guests bundled up and headed into the evening storm.

The couple said they had miscalculated in thinking that the heavy snow would start later than it did. “The snow was two things,” Mr. Radnor said. “Cold and anxiety-producing, but also cosmic and divine.”

Neither slippery driving conditions nor ice chunks accumulating on hairdos and beards could keep their guests away. “We’re like the post office,” said Alyson Hannigan, one of the groom’s “How I Met Your Mother” co-stars.

Pamela Fryman, the sitcom’s director, had one request. “When they renew their vows,” she said, “maybe they can do it in the spring.”

In a blitz of large, shimmering snowflakes, the bride, groom, their siblings and their parents managed to stride down the aisle without falling.

The bride promised to give her groom space. “My first vow is freedom, which also means we are free to stay, or — if this relationship ever evolves in such a way that it is no longer serving our highest good — we are free to go,” she told him. “We know it is choice, not obligation, that makes us want to remain exactly where we are.”

The groom cried as he pledged himself. “I look into the infinity of your green eyes, I know that my not having gotten married until now was not due to some brokenness in me,” he said. “The truth is, I didn’t get married until now because,” he added, “I was waiting for you.”

The ceremony included Jewish wedding traditions and was led by Jacob Azia, a friend of the couple who is a Universal Life Church minister.

As the guests thawed around a large indoor fireplace, the newlyweds peeled off so that the bride’s snow-drenched hair could be restyled as the groom, in his first official act as a husband, knelt at her feet and warmed them with a blow-dryer.

Back in the candlelit lodge, the reception unfolded. Nine friends and relatives gave speeches as the snow continued to fall, and as those who were not among the 115 guests planning to stay in cabins at the venue overnight checked and rechecked the weather and traffic apps on their phones.

Dr. Jacobs and Mr. Radnor tried to focus on the speeches and let the wedding planner and venue staff handle the logistics. “But energetically, in the room, we could feel the stress,” Dr. Jacobs said.

Around 10:30 p.m., a member of the venue staff made an announcement: The roads were not passable and everyone would need to spend the night. This included guests, the 10 members of the wedding band, the event planners, the venue staff members and a reporter and a photographer from The New York Times, a total of 59 extra people.

Some were assigned top bunks in rooms that the couple’s friends had rented for the weekend, while others slept at the venue owner’s on-site residence.

“Once it was announced, ‘No one is leaving here tonight,’ people went into a little bit of surrender mode,” Mr. Radnor said. The band began to play the Beatles song “Oh! Darling” and the newlyweds danced with abandon.

“It was about as analogous to a psychedelic ceremony as you can get,” Dr. Jacobs said.

On This Day

When Jan. 6, 2024

Where Cedar Lakes Estate, Port Jervis, N.Y.

The Eve of the Night Before Two nights before the wedding, Mr. Radnor and Dr. Jacobs dined alone in a heated glass igloo with views on the wedding venue’s property. Dr. Jacobs surprised Mr. Radnor with a collection of their voice memos from when they were dating. “It was so special to hear these earlier versions of ourselves getting to know each other,” he said. “And then to look across the table and realize where we were — moments away from being married.”

Wedding Swag Guests received welcome bags containing incense sticks, an incense dish, CBD tincture and an “intention kit” with paper and a pen. “We find that setting an intention can be a helpful way to drop in and calibrate your internal compass to true north,” the instructions read.

Man’s Best Man Nelson the Dog, the couple’s labradoodle, served as an honorary groomsman (wearing a burgundy bow tie) and was walked down the aisle by Seth Jacobs, one of Dr. Jacobs’s brothers.