Pacific Grove's Monarchs Are Due Back. Last Winter Showed Where in the Grove to Look.

Most of last winter's monarchs at the Monarch Grove Sanctuary spent the season on eucalyptus along the south and southwest edges of the grove, in the sun. Those trees accounted for 94% of all observations. Pines took 5% and Monterey cypress 2%. The interior paths, where the clusters ended up in some earlier years, saw almost none of them.

That pattern comes from the City of Pacific Grove's 2026 sanctuary assessment, written by monarch ecologist Stuart B. Weiss of Creekside Science. He has worked at the sanctuary since 1997. With the 2026-27 season due to begin, the report holds a practical lesson for anyone who lives a few blocks from Ridge Road. While the western population stays this small, the grove does not fill up the way it once did. The butterflies are usually there, but they are hard to find, and where they sit depends on the wind.

A mild winter kept the clusters on the edge

The monarchs follow the weather. Weiss writes that they "crowdsource the microclimate." They leave spots that get too windy, too shady or too warm, and they land where other monarchs have already clustered. They usually start the season on the sunny South Edge and move into the interior when southerly storm winds push them there.

The 2025-26 season sent only a few of them inward. Monterey Airport recorded no fall hourly winds above 20 mph, and only one night all season dropped below 40°F. The butterflies stayed on the South and SW edges all winter, apart from a few on pines in the South Interior just north of the main trail. The similarly mild 2024-25 season followed the same pattern.

Stormier winters looked very different. In 2023-24 the clusters moved from the South Edge to the South Interior by mid-November, into the Interior by early January and to the Driveway by February. In 2022-23, repeated strong storms drove them deep into the North Interior. Weiss explains why the butterflies seemed to favor pines and cypress in those years. The sheltered interior is mostly pine and cypress, so the choice reflects the shelter, not the tree. He also notes they have often clustered on a lone Monterey pine just south of the sanctuary boundary.

So the forecast tells you where to look. In a calm, sunny stretch, the eucalyptus on the south side is the place to start. After a southerly blow, the interior is worth checking.

The windstorm that looked like an exodus

Small numbers make the grove look emptier than it is. The Pacific Grove Museum of Natural History counted 188 monarchs at the sanctuary by mid-November 2025 and more than 200 in mid-December, with a peak of 226 on December 12. Then came the strongest wind of the season, 29 mph hourly peaks on December 24 and 25. Over the next few weeks the count looked like this:

1. December 26: 3 monarchs observed
2. January 2: 131
3. January 7: 25, after several days of steady moderate wind
4. January 17: 203
5. February 7: all butterflies had left the grove

Weiss reads the quick rebound as a sign that the monarchs "scattered rather than emigrated." He adds that individual butterflies and small groups spread through the canopy are hard to spot, so some undercounting after a storm is likely. When only about 200 butterflies are in the grove, missing a group of 5 to 10 changes the picture a lot. Weiss writes that in low-number years it is especially important to watch in the afternoon, when the monarchs settle into their night roosts. According to the report, the Museum's monitors are adjusting their methods to account for this. Weiss credits Natalie Johnson for that update.

For a resident walking over after a winter storm, an empty-looking South Edge on the first morning was not the end of the season last year. Two weeks later, most of the butterflies were back.

Why the county count jumped and the grove's stayed level

The numbers around the grove tell the same story. The Xerces Society's January 29, 2026 release reported 12,260 monarchs statewide in the 2025 Thanksgiving count. That was up from 9,119 in 2024, but still the third-lowest count since tracking began in 1997. Monterey County's total grew roughly sixfold. Pacific Grove's sanctuary count went down slightly.

In the 2025 count, most of the county's monarchs were at one private site near Big Sur, at Esalen. Pacific Grove ranked 16th among California sites, well below its usual spot in the top 10. Since 2001 the sanctuary has averaged 37% of the county's monarchs.

Weiss does not treat this as a sign the grove is failing. Pacific Grove's numbers mostly rise and fall with the statewide population, and the 2025 figure "fall[s] close to the average line" on his long-run trend. The sanctuary also held its butterflies well. It kept 70% of its Thanksgiving count on January 10 and had more than 100% on January 17. Natural Bridges kept 62%, Lighthouse Field 73% and Moran Lake 77%. The Museum still describes the sanctuary as the largest overwintering site in Monterey County and one of the largest publicly accessible sites in California. Esalen's count does not change that, because Esalen is private property.

Work timed around the arrival

How the grove is managed follows from all of this. The City's Environmental Manager, George Fuerst, presented this year's update at the Beautification and Natural Resources Commission's August 18, 2026 meeting. He explained that bird nesting and the monarchs' arrival limit when tree work can happen, so most of it comes in a short window each fall. In his words:

"So usually we kind of have a flurry of work between September and October."

The 2026 plan is short. Crews are to clear and spread out the eucalyptus bark, branches and leaves that have piled up along the South Edge to reduce fire risk, while leaving some debris so a butterfly that falls can climb back up. Other items include removing hazard trees as they are found, thinning crowded cypress northeast of the nectar beds and removing dead trees from a dense eucalyptus stand in the southeast corner. New tree planting is paused, with one exception: a double row of cypress along the boundary with the hotel in the northeast corner. The report notes that last year's recommended cleanup of the forest floor was not carried out, which is part of why it tops this year's list. No public record yet confirms whether the September work has been done.

Weiss is direct about the eucalyptus. "This is not a 'natural' forest," he writes, and the existing non-native eucalyptus, including the 1999 shelterbelt, provides structure the monarchs depend on. The trees that held 94% of last winter's observations are the same trees the cleanup is meant to protect. The work plan was developed in consultation with Fuerst and the City's new arborist, John Kelly, in January and June 2026.

The site also comes with long-standing limits. Fuerst told the commission that the City bought the property in 1992 with about $1 million from a bond measure and about $200,000 from a state grant. A condition of the grant was a conservation easement held by the California Department of Fish and Wildlife. It bars new structures without approval and any commercial use of the grounds.

Before you walk over

As of this writing, the Pacific Grove Museum's sanctuary tracker was last updated September 19, 2026. That update said the monarchs had not yet arrived and that a slow trickle was expected in mid-October. The Museum updates the page weekly once the butterflies start settling. Last year started slowly too. The Western Monarch Count recorded 63 monarchs at Pacific Grove on October 30, 2025.

• Where and when: 250 Ridge Road, open sunrise to sunset every day. Admission is free and no reservations are needed. The site closes only when high winds make visits unsafe.
• Getting there: Parking is free but limited, mostly on nearby streets such as Lighthouse Avenue. The packed-gravel trail is ADA accessible, with a slight downhill slope. Pets are not allowed.
• Docents: Museum volunteers are often on site from October through February, generally from 11 a.m. to 3 p.m., weather permitting.
• The count calendar: The Xerces Society's 2026 early-season count runs October 17 through November 1. Last season's numbers peaked in late November through early December, the usual pattern since 2013.
• On the calendar: This year's Butterfly Parade was held October 3. The Museum's free Science Saturday: Monarch Magic! runs November 28, 2026, from 10 a.m. to 3 p.m.
• Federal status: As of the U.S. Fish and Wildlife Service's September 21, 2026 update, the monarch was not federally protected, and the proposed threatened listing had no final ruling.

If the weather stays calm, start with the sunny eucalyptus on the South Edge. If a southerly storm has just blown through, give it a few days and an afternoon visit before deciding the butterflies are gone.

J.R. Rouse Properties Group has been based in Pacific Grove for decades, and the sanctuary's season is part of the town we work in. If you're thinking about what life near Ridge Road or anywhere in Pacific Grove could look like for you, we'd be glad to talk it through. Schedule a free consultation.

This article is general information, not legal, tax or financial advice. Consult a qualified professional about your situation.