Saturday here in the Northern Hemisphere heralds the official arrival of a season long-anticipated by Minnesotans. A bit of planetary harmony awash in numbers.

Summer arrives with the solstice at exactly 4:44 p.m. — that moment when the sun hits at its northernmost point on Earth, tilted on its polar axis at 23.5 degrees. The farther north, the longer the day. The sun stays above the horizon all day at the North Pole.

In the metro, we’ll be blessed with — more numbers — 15 hours, 37 minutes of daylight, while Up North in Bemidji, for example, the sun will set 17 minutes later, at 9:19 p.m.

Summer, of course, also is a state of mind. A few Minnesota observers of the natural world see the season through a broader lens. Here is what they are thinking about and observing:

Embrace twilight …

Bob King of Duluth, aka “Astro Bob” for his popular books and astronomy blog, sees a cadence to natural events, underscored by the solstice.

“It always feels like a bit of journey, from that first day of winter to the first day of summer,” King said. “You’re climbing from the bottom of the curve to the top — which is what will happen on the 20th at 4:44 p.m.

“It’s a rhythm, is what it’s really about. And in the summer, the rhythm is the incredibly long days vs. the short nights.”

King said he loves the dreaminess of evening twilight and later sunsets, complemented by fragrant trees and flowers in bloom. “I love that evening feel,” said the retired journalist, who added that he forces himself to stay up late, edging toward 1 a.m., for maximum stargazing.

… and the Milky Way

The Milky Way starts to climb up the eastern sky this time of summer (like “a grand, smoky rainbow,” King said), a section of the phenomenon that spans the “W” of the constellation of Cassiopeia through the Northern Cross all the way down to Sagittarius.

“There is just something about it that is energizing for me to see. It’s beautiful,” King said. “It’s the galaxy — it’s like, ‘Oh, the galaxy has returned.’ ”

King said on a moonless night in a dark eastern sky — away from Duluth’s city lights — it can’t be missed. He said people might miss the galaxy in other seasons. Summer, then, is an opportunity. Get to a place with few lights, King said, and use a telescope, pulling it along the arc of the Milky Way from east to south. He said he sees star clusters, nebulas and patterns of stars. Binoculars work, too. (King said the website lightpollutionmap.info is a road map to the darkest skies in the state — and everywhere.)

“There are tens of thousands of stars that pass by,” King said. The Milky Way is even easier to spot in August because this section will have moved overhead, he said.

Flower power

As much as spring is a season of renewal, summer is about growth for Jim Gilbert of Waconia, a longtime environmental studies teacher and naturalist (and longtime Outdoors Weekend contributor).

Gilbert follows the bloom of the showy pink and white lady’s slipper to gauge summer’s start. When it blooms, he is transported in memory back decades when he listened to a botany professor at the University of Minnesota.

“He said, ‘When the showy pink and white lady’s slipper blooms, that is to me the first day of summer,’ ” Gilbert said. “And I’ve never forgotten that.”

This year, Gilbert scribbled June 8 in his notebook for the state’s official flower. “The showy pink and white lady slipper is blooming nicely throughout much of the state,” he said.

Growth occurs in all realms, Gilbert added, thinking about spruces and pines, wild roses and strawberries, even loon hatchlings set tight to their parents’ backs. “We are seeing nature at its best around the solstice and leading into the summer. “

North vs. south

For Gilbert, summer also is about where flowers and plants blossom. For example, the far northwest reaches of the state currently get as much as 40 minutes more daylight than southeast Minnesota. The farther north, the longer the days because of Earth’s position toward the sun this time of year.

“By the time we get to July 4th, things start blooming in the north before they bloom in the south,” Gilbert said.

Lighting up the solstice

Gilbert spotted his flash of a firefly June 3, and he said they peak around the state at the solstice.

“Now, they’re unbelievable. They are all over the place,” said Gilbert, who marveled that there are as many 15 species of the insect, some of which flash longer, or others that glow a deeper yellow or brighter white. Think more lumens.

“I didn’t know that. I am learning all the time,” Gilbert said. “I thought it was one kind of firefly, and I’ve taken three entomology classes. I didn’t even know that. … No wonder some looked different to me.”

In fact, King is studying up, too. He said they are a welcome distraction on his nightly adventures (“a whole group of new stars … the ground version”).

Busy birds

Summer isn’t the best time for bird-watching, said Val Cunningham of St. Paul. Feeders are quieter because migrants have passed through, and Minnesota resident birds are stuffing their young with insects. Nevertheless, action abounds.

Cunningham writes regularly about the bird world in the Star Tribune’s Variety section.

She said robins are ever-present these days. For one, they nest and live their lives so close to humans, with the noisy young yelling for another worm and young males practicing discordant songs as part of the chorus at dawn.

Cunningham said she — and her readers — have heard and seen an abundance of orioles. “This does seem to be the year of the oriole,” she added. “They are just everywhere and you hear them still singing in mid-June. I heard one yesterday. It’s kind of a different song. It’s not their exultant springtime song, but it’s kind of like ‘Looking for insects here … oop, found one.’ ”

If residents only had a heat map of their neighborhood block to pinpoint nests in trees and shrubs, they would marvel at all of their winged residents.

“There’d be nests all over,” Cunningham said. “There’d be catbirds and cardinals and robins and chickadees and sparrows, maybe hummingbirds, and house finches. It’d be just so fun to see that.”

So much to experience, so much playing out as summer takes center stage in Minnesota.

“The solstice to me means abundance, and it’s all about the abundance of everything in the summer. Whether it’s the stars in the form of the Milky Way or the all the fireflies,” King said. “It’s just this abundance. I just try to plug in and feel that and enjoy it as much as I can.”