May is peak spring across Washington — the coast rhododendron blooms in the western woods, the last warblers and flycatchers arrive on territory, the Salish Sea seabird colonies fill, and the lowland garden finally turns warm enough for tomatoes near month's end.
Week by week in May
April 30 – May 6
- The coast rhododendron, the state flower, begins to bloom pink through the open conifer woods of the Kitsap and Olympic peninsulas.
- Westside forests ring with the spiraling flute song of Swainson's Thrush, the sound of the Northwest spring.
- The Eta Aquariid meteors, debris of Halley's Comet, peak in early May, best in the predawn southern sky.
May 7–13
- Salish Sea colonies fill with Rhinoceros Auklets, Pigeon Guillemots, and Tufted Puffins at Protection Island and the outer coast.
- After mid-May, with soils finally warm, set out tomatoes, peppers, and squash and direct-sow beans and corn on the westside.
- The first western-valley strawberries join peaking asparagus, peas, radishes, and spring onions at the markets.
May 14–20
- Lorquin's Admirals begin flying along willow-lined streams, defending sunlit perches against intruders, even birds.
- East of the Cascades the shrub-steppe sings with Sage Thrasher, Lazuli Bunting, Bullock's Oriole, and Brewer's Sparrow.
- Bitterroot, mariposa lily, and late balsamroot hold the final great bloom on the warming Columbia Gorge slopes.
May 21–27
- Pacific madrone sets clusters of white urn-shaped flowers on Puget Sound bluffs as oceanspray readies its creamy plumes.
- Mulch beds against the coming dry Northwest summer, stake tomatoes and dahlias, and keep succession-sowing lettuce and greens.
- Band-tailed Pigeons work the elderberry and Vaux's Swifts wheel over the canopy as breeding hits full stride.
May 28 – June 3
- Oceanspray foams creamy-white along westside roadsides and the first glacier lilies push up at the receding subalpine snowline.
- Yakima and Wenatchee cherries begin — Bings first, then blush-yellow Rainiers, Washington's signature June fruit.
- Woodland Skippers begin their long late-spring-into-summer flight in westside meadows and gardens.
Birds This Month
May is the height of breeding song and the last of migration. Westside forests ring with Swainson's Thrushes (their spiraling flute song is the sound of the Northwest spring), Western Tanagers, Black-headed Grosbeaks, Wilson's and MacGillivray's Warblers, Pacific-slope Flycatchers, and Vaux's Swifts. Rufous and Anna's Hummingbirds are nesting, and Band-tailed Pigeons work the elderberry.
On the Salish Sea, the seabird colonies are full — Rhinoceros Auklets, Pigeon Guillemots, Tufted Puffins at Protection Island and the outer coast, Pelagic and Double-crested Cormorants, and nesting Bald Eagles. East of the Cascades the shrub-steppe is alive with Sage Thrashers, Brewer's and Vesper Sparrows, Lazuli Buntings, and Bullock's Orioles, while the ponderosa forests hold Western Bluebirds, Cassin's Finches, and White-headed Woodpeckers.
What's Blooming
May brings the state flower into its glory: the coast rhododendron blooms pink through the open conifer woods of the western lowlands, finest on the Kitsap and Olympic peninsulas. The westside forest floor peaks — native trillium fading to purple, vanilla leaf, queen's cup, star-flowered Solomon's seal, bunchberry, and the lush new fronds of sword and lady fern. Roadsides foam with oceanspray and cow parsnip.
The shrub-steppe and Columbia Gorge hold their final great bloom — late balsamroot and lupine, bitterroot, mariposa lily, larkspur, and death camas on the warming slopes. Wet south Puget prairies still carry the last camas. The high country is just beginning to wake at lower elevations, but the famous subalpine meadows of Mount Rainier and the Olympics remain under snow, their avalanche-lily display still two months away.
Garden This Month
May is when the westside garden finally goes summer. After the soil warms past mid-month, set out tomatoes, peppers, eggplant, squash, cucumbers, and basil, and direct-sow beans, corn, and cucumbers — wait for warmth, since cold Puget Sound soil stalls these crops. Keep succession-sowing lettuce, carrots, beets, and cilantro, plant out leeks and winter brassicas for fall, and stake the dahlias. Thin fruit on apples and pears for better size.
Slugs and cool-season pests remain the westside gardener's chief foe, so protect new transplants. Mulch beds to conserve moisture, because the famously dry Northwest summer is coming and irrigation will soon matter. East of the Cascades, the Columbia Basin garden is in full warm-season planting after the last frost — tomatoes, peppers, melons, corn, and beans all go in for the intense, sun-drenched eastern growing season.
Zone 6b (eastern valleys & foothills): the Columbia Basin season accelerates. After the last frost, plant out warm-season crops and direct-sow beans, corn, and melons into the quickly warming soil for the short, hot eastern summer.
Zone 7b (Puget lowland & coastal valleys): after mid-May, with soils finally warm, set out tomatoes, peppers, squash, cucumbers, and basil and direct-sow beans and corn. Keep planting succession lettuce and greens, and stay vigilant on slugs.
Zone 8a (Puget Sound shore & San Juan Islands): the warmest gardens plant out the full summer range now — tomatoes, peppers, squash, beans, and cucumbers — and sow the first sweet corn. Mulch to hold the spring moisture into the dry summer ahead.
What's at the Farmers Market
May markets surge with spring. Asparagus from the Columbia Basin and Walla Walla peaks, joined by the first strawberries from western valleys, rhubarb, radishes, spring onions, peas and pea vines, salad turnips, and abundant tender lettuces and spinach. The first cut herbs and overwintered greens fill the westside stalls.
From the water come spring spot prawns, fresh halibut from the coast and Salish Sea as the season opens, and the first king salmon. Choose firm asparagus with tight tips and stand it upright in water; pick fully red, dry strawberries and refrigerate them unwashed in a single layer, using fast since they don't keep. Farmers markets are now open statewide — Olympia, Ballard, Pike Place, Spokane, and dozens more — at the start of their long peak season.
Night Sky This Month
May's warmer, longer dusks make for pleasant stargazing, though the nights grow short as solstice nears. The dark-sky strongholds remain the dry east: Goldendale Observatory State Park above the Columbia Gorge, Sun Lakes–Dry Falls, and the wide Methow Valley and Columbia Basin skies, where spring star parties are in full swing. Westside viewers grab the clear, mild nights between the last spring fronts.
The spring sky shines: Leo sinks westward while Boötes with brilliant Arcturus, Virgo, and the rising Hercules and its globular cluster (a fine binocular target) climb the east. By late evening the summer Milky Way begins to clear the horizon. The Eta Aquariid meteors, debris of Halley's Comet, peak in early May, best in the predawn south. For this year's exact timing, planet positions, and aurora outlook, see the printable Washington night-sky guide.
Butterflies & Pollinators
May is a rich butterfly month across Washington's lowlands and dry country. Westside gardens, parks, and forest edges host Western and Pale Tiger Swallowtails, Anise Swallowtails, Western Spring Azures, Cabbage and Pine Whites, Lorquin's Admirals beginning to fly along the streams, and the first fritillaries and commas.
The shrub-steppe and Columbia Gorge are at their butterfly peak: checkerspots, blues, coppers, skippers, Becker's White, and patrolling swallowtails work the lupine, balsamroot, and buckwheat. Hilltops on the dry slopes draw males circling for mates. The high-elevation specialties — the parnassians, alpine fritillaries, and meadow blues of Rainier and the Olympics — are still waiting on the melting snow, their flight tied to the subalpine bloom that won't arrive until midsummer.
What to plant for them is in the Washington native plants guide
Trees This Month
May fills out the Washington canopy. Pacific dogwood opens its large white bracts through the westside forest, the native Pacific madrone sets clusters of white urn-shaped flowers on the bluffs, and cascara, bitter cherry, and Pacific crabapple bloom along the edges. Oceanspray readies its creamy plumes, and black hawthorn flowers in the hedgerows. The conifers push bright new growth — western hemlock tipped in pale green, Douglas-fir, grand fir, and Sitka spruce all flushing.
The bigleaf maple is in full leaf, casting deep shade, and the riverside black cottonwood releases its drifting white seed-fluff along the lowland rivers. East of the Cascades, the ponderosa pine sheds clouds of pollen and warms its vanilla-scented orange bark, while the quaking aspen shimmers in full leaf and the water birch and cottonwood green the canyon bottoms over the still-flowering shrub-steppe.
The Washington native plants guide covers what grows with them
Weather & Daylight
Across Washington, a typical May day averages a high near 64°F and a low near 42°F, with about 2.5 inches of precipitation — statewide averages from the 1991–2020 U.S. climate normals.
Warm, pleasant days near 64F with mild nights invite open windows, as rainfall tapers to occasional afternoon showers.
| Average high | 64°F |
|---|---|
| Average low | 42°F |
| Precipitation | 2.5 in |
| Sunrise (mid-month) | 5:28 PT |
| Sunset (mid-month) | 20:33 PT |
Figures are statewide averages over the 1991–2020 U.S. climate normals; local conditions vary with elevation and distance from the coast. Sunrise and sunset are computed for a midstate point on the 15th (PT).
Next month's version of this page, by email
One short note when Washington's next month turns — what's arriving, blooming, and worth a night outside.
Go deeper with the Washington guides
The complete Washington birding, native-plant, and night-sky references — or the whole year, week by week, in one book.
Same month elsewhere: May in West Virginia · May in Wisconsin · May in Wyoming