# Boulder Reef, United States: what it is and when to go

> Boulder Reef is a reef in Rosario Strait, Skagit County, Washington, United States of America (Anacortes). Interests: Beaches and Diving. The best time to visit is June to September. In June there are 15 h 54 of daylight, and in December, 8 h 05. It has an article in one Wikipedia, so it is not one of the busiest places in United States: one to enjoy at a calmer pace. Here is what it is, where it lies, when to come, how to get there and what else is nearby to turn it into a trip.

- Address: https://kokai.app/en/paises/america/estados-unidos/boulder-reef/
- Reviewed on: 2026-10-08
- Language: en

## In a nutshell

- **What it is:** Reef in Rosario Strait, Skagit County, Washington, United States of America · Beaches, Diving
- **Where:** United States
- **Best time:** June to September.
- **Nearest airport:** SFO San Francisco, 1,226 km as the crow flies
- **Coordinates:** 48.63481, -122.69075

## What it is and where

Boulder Reef is a reef in Rosario Strait, Skagit County, Washington, United States of America (Anacortes). It has an article in one Wikipedia, so it is not one of the busiest places in United States: one to enjoy at a calmer pace.

It is in [Anacortes](https://kokai.app/en/paises/america/estados-unidos/anacortes/), where this site lists 16 more places to see, 15 km from the centre.

Its coordinates are 48.63481, -122.69075; the nearest main airport is San Francisco International Airport (SFO, San Francisco), 1,226 km as the crow flies. How to get around United States (train, car, bus) is covered in [its country guide](https://kokai.app/en/paises/america/estados-unidos/#moverse).

- [Where it is](https://www.google.com/maps/search/?api=1&query=48.634812%2C-122.690753)
- [Directions](https://www.google.com/maps/dir/?api=1&destination=48.634812%2C-122.690753)

It is one of the [Beaches](https://kokai.app/en/paises/america/estados-unidos/playa/) and [Diving](https://kokai.app/en/paises/america/estados-unidos/submarinismo/) places in United States. In [Kokai](https://kokai.app/en/) it is already on your trip map next to the places you save yourself, and it goes into a day's plan with one tap.

## When to go

The best time to visit Boulder Reef is **June to September**.

| Mes | Época | Hours of daylight |
| --- | --- | --- |
| January | Better not | 8 h 30 |
| February | Better not | 9 h 56 |
| March | Better not | 11 h 34 |
| April | Possible | 13 h 27 |
| May | Possible | 15 h 02 |
| June | Best time | 15 h 54 |
| July | Best time | 15 h 33 |
| August | Best time | 14 h 09 |
| September | Best time | 12 h 20 |
| October | Possible | 10 h 31 |
| November | Better not | 8 h 54 |
| December | Better not | 8 h 05 |

In June there are 15 h 54 of daylight, and in December, 8 h 05. Daylight hours are calculated from the site's latitude for the 15th of each month; when planning a full day on foot they matter as much as the weather.

| What you come for | Best time | Possible |
| --- | --- | --- |
| Beaches | June to September | April to May and October |
| Diving | June to September | April to May and October |

It is not the same trip whatever you come for: Boulder Reef has a different season depending on what you want to do here, and [Kokai](https://kokai.app/en/) puts it in the right month for you.

When to go to United States in general, with its festivals and peak seasons, is in [its country guide](https://kokai.app/en/paises/america/estados-unidos/#cuando-ir).

## Before you go to United States

To enter United States there are 9 things to sort out before you leave, starting with “Book national parks and cars in advance”: they are all, with their deadlines, in [the United States checklist](https://kokai.app/en/paises/america/estados-unidos/#antes-de-salir). Currency: US dollar (USD); plugs: Type A and B · 120 V · 60 Hz (you need an adapter, and check your devices' voltage); emergencies: 911 for everything.

In [Kokai](https://kokai.app/en/) you tick off the checklist inside your trip, and each item reminds you when it is time to do it.

## What is nearby

- [Buckeye Shoal](https://kokai.app/en/paises/america/estados-unidos/buckeye-shoal/): Reef in Rosario Strait, Skagit County, Washington, United State sf America · 3.1 km
- [Cypress Reef](https://kokai.app/en/paises/america/estados-unidos/cypress-reef/): Reef in Rosario Strait, Skagit County, Washington, United State sf America · 3.3 km
- [Bakers Reef](https://kokai.app/en/paises/america/estados-unidos/bakers-reef/): Reef off the western shore of Lummi Island in Whatcom County, Washington, United States of America · 5.5 km
- [Deepwater Bay](https://kokai.app/en/paises/america/estados-unidos/deepwater-bay/): Bay on Cypress Island in Skagit County, Washington, United States of America · 8.5 km
- [Clark Island](https://kokai.app/en/paises/america/estados-unidos/clark-island-marine-state-park/): Island of the San Juan Islands in Washington state, United States · 9.1 km

Distances are as the crow flies. Everything else is in [the United States guide](https://kokai.app/en/paises/america/estados-unidos/).

## More in United States: Beaches

- [Coney Island](https://kokai.app/en/paises/america/estados-unidos/coney-island-beach/): coastal neighborhood in Brooklyn, New York City, New York, USA
- [Waimānalo Beach, Hawaii](https://kokai.app/en/paises/america/estados-unidos/waimanalo-beach/)
- [Maro Reef](https://kokai.app/en/paises/america/estados-unidos/maro-reef/): shoal in Honolulu County, Hawaii, United States
- [Glass Beach](https://kokai.app/en/paises/america/estados-unidos/glass-beach/): beach in northern California, USA
- [Waipiʻo Valley](https://kokai.app/en/paises/america/estados-unidos/waipio-beach/): valley on Hawaii Island, Hawaii
- [Baker Beach](https://kokai.app/en/paises/america/estados-unidos/baker-beach-clothing-optional-area/): beach on the peninsula of San Francisco, California, United States

Every United States place under Beaches, each with its season, is on [its page](https://kokai.app/en/paises/america/estados-unidos/playa/).

## Frequently asked questions

### What is Boulder Reef?

It is a reef in Rosario Strait, Skagit County, Washington, United States of America. It has an article in one Wikipedia, so it is not one of the busiest places in United States: one to enjoy at a calmer pace.

### When is the best time to visit Boulder Reef?

June to September. In June there are 15 h 54 of daylight, and in December, 8 h 05.

### How do you get to Boulder Reef?

The nearest main airport is San Francisco International Airport (SFO), 1,226 km as the crow flies. From there, [directions](https://www.google.com/maps/dir/?api=1&destination=48.634812%2C-122.690753) opens the route on the map, and how to get around United States is explained in [its country guide](https://kokai.app/en/paises/america/estados-unidos/#moverse).

### How do I add it to my trip?

With one tap. In Kokai it is already on the United States map, next to the places you save yourself: add it to a day's plan, give it a time and, if you like, get a reminder when you pass nearby.

### What else is around here?

Nearby you have [Buckeye Shoal](https://kokai.app/en/paises/america/estados-unidos/buckeye-shoal/), [Cypress Reef](https://kokai.app/en/paises/america/estados-unidos/cypress-reef/), [Bakers Reef](https://kokai.app/en/paises/america/estados-unidos/bakers-reef/). The rest is in [the United States guide](https://kokai.app/en/paises/america/estados-unidos/).

Data from [OpenStreetMap](https://www.openstreetmap.org/way/1470404677), licensed under the ODbL, and from [Wikidata](https://www.wikidata.org/wiki/Q49614145), CC0. Daylight hours are calculated from the latitude. More in [credits](https://kokai.app/en/aviso/#creditos).