When do swallows leave California?

Most Barn Swallows have left California by mid September, when reports fall below half their usual rate. Stragglers are still reported until the second week of October.

When is the best time to see swallows in California?

The Barn Swallow is reported most often in the second week of August, on about 23% of California checklists.

Which swallows are in California?

Barn Swallow, Cliff Swallow, Tree Swallow, and Violet-green Swallow are reported regularly; the Barn Swallow is the most common.

4 swallow species in California

When Do Swallows Arrive in California?

Photo: Diego González Dopico, CC BY 4.0 via iNaturalist

Barn Swallows, Cliff Swallows, and Tree Swallows are the swallows you are most likely to see in California. Barn Swallows reach California in early March, are common by late March, peak in the second week of August (23% of checklists), and most are gone by mid September.

When to look

First arrivalsMar 1-7early March

Common byMar 22-31late March

PeakAug 8-14the second week of August

Most gone bySep 15-21mid September

Best: the second week of August. First arrivals early March; most are gone by mid September. Peak: on about 23% of California checklists.

Janrare
Febrare
Marcommon
Aprcommon
Maypeak season
Junpeak season
Julpeak season
Augpeak season
Seppeak season
Octuncommon
Novnot usually seen
Decrare

Darker months: more checklists report it. Outlined: peak month.

Swallows in California, species by species

Species	First arrivals	Common by	Peak	Most gone by	Peak %
Barn Swallow	Mar 1-7	Mar 22-31	Aug 8-14	Sep 15-21	23%
Cliff Swallow	Mar 1-7	Apr 1-7	Jun 8-14	Aug 8-14	20%
Tree Swallow	Jan 15-21	Feb 15-21	Apr 22-30	Jul 15-21	17%
Violet-green Swallow	Feb 8-14	Mar 8-14	May 22-31	Jul 22-31	14%

Barn Swallow
Cliff Swallow
Tree Swallow
Violet-green Swallow

Share of complete checklists reporting each species, by week (4 per month). Gaps: fewer than 10 checklists that week.

Frequency is the share of complete checklists in California that listed the bird, 2016–2025. It is not a head count, and it follows where and when people go birding. How to read it.

Where in California

Best counties for Barn Swallow

Share of checklists at the peak

Yolo CountyBest late July · 1189 checklists that week, 67,424 in all54%
Humboldt CountyBest mid August · 1626 checklists that week, 95,963 in all52%
Del Norte CountyBest mid August · 335 checklists that week, 16,363 in all45%
San Joaquin CountyBest early August · 490 checklists that week, 33,237 in all44%
Solano CountyBest late July · 482 checklists that week, 25,325 in all42%
Napa CountyBest the second week of August · 283 checklists that week, 18,976 in all42%

All swallows in California

5 species are reported regularly: 5 are summer visitors.

#	Species	Pattern	First arrivals	Peak	Peak %
1	Barn Swallow	Summer visitor	Mar 1-7	Aug 8-14	23%
2	Cliff Swallow	Summer visitor	Mar 1-7	Jun 8-14	20%
3	Tree Swallow	Summer visitor	Jan 15-21	Apr 22-30	17%
4	Violet-green Swallow	Summer visitor	Feb 8-14	May 22-31	14%
5	Northern Rough-winged Swallow	Summer visitor	Feb 8-14	Apr 22-30	13%

Common questions

When do swallows arrive in California?: Barn Swallows reach California in early March, are common by late March, peak in the second week of August (23% of checklists), and most are gone by mid September.
When do swallows leave California?: Most Barn Swallows have left California by mid September, when reports fall below half their usual rate. Stragglers are still reported until the second week of October.
When is the best time to see swallows in California?: The Barn Swallow is reported most often in the second week of August, on about 23% of California checklists.
Which swallows are in California?: Barn Swallow, Cliff Swallow, Tree Swallow, and Violet-green Swallow are reported regularly; the Barn Swallow is the most common.