When do tree swallows arrive in Washington?
The Tree Swallow is a summer breeder in Washington — here is when to expect it, when it leaves, and how to be ready.
Tree Swallow timing in Washington
- Arrives
- Around April
- Leaves
- By July
- Status here
- Summer breeder
- Nesting season
- May–June
- Present roughly
- April–July
In Washington, tree swallows are present through the warm months, arriving around April and heading south again by July.
These windows are set by latitude: Washington sits in the middle part of this species' range, so timing here tracks the continental average closely. In any given year, weather can move the first arrivals by a week or two either way.
Month by month in this state
Highlighted months are when tree swallows are expected in Washington. The edges of the window are the interesting weeks — first arrivals and last departures vary most from year to year.
Getting ready before they arrive
The week before April is the time to act. Have feeders cleaned, filled and out by early April — the first tree swallows into Washington are scouting for reliable food, and a station that's ready early gets added to their route.
Tree swallows nest in cavities, so boxes need to be up and cleaned before arrival — a box mounted after they've claimed territories will usually sit empty until next year. Tree Swallow nest box dimensions and mounting →
Once nesting begins around May, adults switch to protein-rich food for their young and visits to feeders become quick and purposeful. Expect the busiest activity at dawn.
What tree swallows eat while they're here
- Flies, mayflies and dragonflies
Tree swallows readily take bluebird-style nest boxes; mount boxes in pairs 15–25 ft apart to share with bluebirds.
Full Tree Swallow diet guide → · Best feeder for tree swallows →
Native plants that hold tree swallows in Washington
Food keeps a migrant for a day; habitat keeps it for the season. These Washington-native plants are known to attract tree swallows:
Insect-rich in fall and seed in winter.
Catkin seed feeds redpolls and siskins all winter.
Dark summer fruit and heavy caterpillar load.
Seeds and bark insects; pygmy nuthatch and woodpecker habitat.
Late-season bloom supports insects; seed for sparrows.
Acorns and a rich insect community in the Pacific Northwest.
Seed for crossbills, siskins and chickadees.
Early catkins draw insects for arriving warblers and hummingbirds.
Keep exploring
Frequently asked
When do tree swallows arrive in Washington?
tree swallows typically arrive in Washington around April, with nesting underway by May. Timing can shift a week or two with the weather in any given year.
When do tree swallows leave Washington?
Most tree swallows have left Washington by July. They spend the winter farther south and return the following spring.
Do tree swallows stay in Washington all year?
No — in Washington the Tree Swallow is a summer breeder, present roughly April–July. Outside that window it is rarely seen in the state.
What should I put out before tree swallows arrive in Washington?
Have feeders up and clean by early April — first arrivals scout reliable food sources. Good offerings for this species: flies, mayflies and dragonflies.
Sources
- Tree Swallow — All About Birds, Cornell Lab of Ornithology
- Tree Swallow life history — Cornell Lab of Ornithology
- Tree Swallow — Audubon Guide to North American Birds
- NestWatch nest box plans and species requirements — Cornell Lab
- eBird region overview and bar charts — Washington
- USDA Plant Hardiness Zone Map (2023)
- Audubon Native Plants Database
Timing reflects typical patterns for the region as a whole; local dates vary with elevation and year. Check the linked eBird bar charts for your county.