| Small Owls |
Northern Pygmy Owl
 | Length: 5.9–6.7 inches
Wingspan: 12 inches | Native | Common throughout the state, excluding a few places like the Central Valley, the Modoc Plateau, and a few arid regions with a distinct lack of trees | Spring to early summer (Late April to June) |
Burrowing Owl
| Length: 9-11 inches
Wingspan: 21-24 inches | Native | Lives underground in places like the Central Valley, the Imperial Valley, the Mojave Desert, and even coastal areas like the San Francisco Bay | Late winter to early spring (February to August) |
Elf Owl
| Length: 4.9-5.7 inches
Wingspan: 10.5 inches | Native | Limited range, spotted infrequently in San Bernardino as well as in riparian habitats close to the Colorado River | Late spring to summer (April to July) |
Flammulated Owl
| Length: 6.5-7.5 inches
Wingspan: 12-15 inches | Native | Fairly common in northwestern California, around the Sierra Nevada foothills, Yosemite National Park, and Sequoia National Forest | Late spring to early summer (mid-April to July) |
| Western Screech Owl | Length: 8.7 inches
Wingspan: 22 inches | Native | Common in wooded areas, with sightings in the Sierra Nevada, as well as parks in urban areas like Griffith Park in LA | Late winter to early summer (February to May) |
| Whiskered Screech Owl | Length: 6.3-7.9 inches
Wingspan: 17.3 inches | Accidental | Rare, with a few occasional sightings in southern California along the Colorado River in places like Blythe and the Imperial Valley | Late spring to early summer (April to May); breeding populations have been observed in February in California |
Northern Saw-whet Owl
| Length: 7 – 8 inches
Wingspan: 17-22 inches | Native | Fairly common in northern California, with sightings in the Klamath Mountains, the Lassen National Forest, and around the Oregon border | Spring (March to April) |
Boreal Owl
| Length: 8.7–10.6 inches
Wingspan: 20–24 inches | Accidental | Extremely rare, limited to a few unconfirmed sightings | Early February to early May, depending on the availability of prey |
| Large Owls |
Barn Owl
| Length: 12-16 inches
Wingspan: 42-43 inches | Native | Extremely common except in a few mountainous areas, with most sightings in the Central Valley | Year-round, with peaks in late winter and spring (March to June) |
Great Horned Owl
| Length: 18-25 inches
Wingspan: 40-60 inches | Native | Very common in California and can be spotted year-round, with sightings in the Central Valley, the Los Angeles Basin, and the Sierra Nevada | Late fall to early winter (November to January) |
| Barred Owl | Length: 16-24 inches
Wingspan: 16-24 inches | Native | Common in old-growth forests, it has thrived throughout the state, especially in the Sacramento River Delta and the Humboldt Redwoods State Park | Late winter to spring (February to April) |
| Snowy Owl | Length: 20-27 inches
Wingspan: 49-58 inches | Native | While this owl remains rare, there have been enough sightings to verify its existence here | Varies by region and based on prey availability (any time between May and September) |
Long-eared Owl
| Length: 13-16 inches
Wingspan: 24-40 inches | Native | While this owl remains common, it has been extirpated from the Central Valley and the southern coast | Late winter to Spring (February to April) |
Short-eared Owl
| Length: 13-17 inches
Wingspan: 33-43 inches | Native | Relatively uncommon, with most sightings taking place in northeastern California around Suisun Marsh | Varies, often in early spring (March to September) |
Spotted Owl
— Northern
— California
| Length: 17 inches
Wingspan: 45 inches | Native | Both sub-species can be seen in the southern Cascade Range in northern California as well as in the Sierra Nevada and the Transverse, the Peninsular, and the Coast Ranges | Early spring to late summer (February to August) |
Great Gray Owl
| Length: 24-33 inches
Wingspan: 4-5 feet | Native | Relatively rare, with most sightings in the Sierra Nevada and certain counties like Lassen, Modoc, and Siskiyou | Spring to early summer (March to May) |
