Weather StoryAlmanac, microseasons, and the day's weather story.

SeaTac, Washington Weather

Fireweed Ignites. Day 14 of summer. Read this microseason across nine climate regions →

SeaTac weather forecast — hour by hour, 7-day outlook, NOAA radar

SeaTac, WA
Saturday, July 4 at 11:47 AM
60
°
Overcast
Feels like
59°
Humidity
76%
Wind
6 mph
Sunrise
10:18 PM
Sunset
2:08 PM
SeaTac, WA
Hour by hour · 24h
24-Hour ForecastSeaTac, WA: 24-hour forecast. Temperatures range from 53 to 71 degrees Fahrenheit.
L 53°H 71°
SeaTac, WA
7-day forecast
  1. Today
    Jul 4
    Overcast
    —
    —
    71°56°—
  2. Sunday
    Jul 5
    Overcast
    —
    —
    73°53°+2°
  3. Monday
    Jul 6
    Overcast
    —
    —
    85°51°+12°
  4. Tuesday
    Jul 7
    Overcast
    —
    —
    84°52°-1°
  5. Wednesday
    Jul 8
    Light Drizzle
    10%
    0.01″
    69°57°-15°
  6. Thursday
    Jul 9
    Overcast
    —
    —
    78°50°+9°
  7. Friday
    Jul 10
    Clear
    —
    —
    84°51°+6°
SeaTac, WA
Next 24 hours · Cool now
48°62°76°6a12p6p12anow 59°high 71°low 53°
SeaTac, WA
Anemometer · 24h winds · from true
NESW
From · True
SW
231° · backing 12°
Direction
SW
231°
Sustained
6
mph
Gust
7
mph
Peak 24h
10
avg 5
Beaufort · 2 · LIGHT BRZ
0
CALM
<1
1
LIGHT AIR
1–3
2
LIGHT BRZ
4–7
3
GENTLE BRZ
8–12
4
MOD BRZ
13–18
5
FRESH BRZ
19–24
6
STRONG BRZ
25–31
7
NEAR GALE
32–38
24h · sust vs gust · mph
avg 5 · pk 10 @ 10:00p
01020MPHB1B2B3B4B5-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 219SUSTGUST
−24h−18h−12h−6hnow
A whisper of wind — leaves barely shift on the trees.
SeaTac, WA
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
1006.8
+0.5 mb in 3h · steady · 29.73 inHg
Now
1006.8
mb
3h
+0.5
mb
12h
+2.4
mb
24h
+1.2
mb
Regime · RAIN
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 1004–1007
1000STORM|RAIN10051010RAIN|CHG1015CHG|FAIR-21h-18h-15h-12h-9h-6h-3h-24hNOW1006.41004.01006.4
−24h−18h−12h−6hnow
Damp, unsettled regime — wet weather lingers nearby.
SeaTac, WA
Air quality
44
AQI
Good
↑+7 in 6h

AQI 44 (Good), driven by PM2.5. AQI up 7 over the last 6 hours (gradual rise). PM2.5 at 6.9 µg/m³ (AQI 38) with a 0.76 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.

OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.

PM 2.5DRIVERGood
6.9μg/m³
PM 10Good
9μg/m³
NO₂Good
5μg/m³
OzoneGood
42μg/m³
UV IndexModerate
3.9

What's driving it

PM × Wind × Precip

PM2.5 at 6.9 µg/m³ (AQI 38) with a 0.76 fine-to-coarse ratio and 6 mph wind — combustion smoke trapped in calm air, not road dust.

PM2.5/PM10
0.76
Wind
light
Recent rain
0h in last 6h
Pattern
stagnant smoke

Trends

Seven days of AQI and PM2.5.

Hourly air-quality data from the Copernicus Atmosphere Monitoring Service, charted across the past and next several days. Dashed lines mark the AQI breakpoints at 50 (Good → Moderate) and 100 (Moderate → Unhealthy for Sensitive Groups).

7-DAY AQI TREND50100SATSUNMONTUEWEDTHUFRISAT7-DAY PM2.5 TREND · μg/m³300
SeaTac, WA
Sky cover · visibility · 24h
Cloud cover
100%
OVERCAST
100%0%−24h−18h−12h−6hnow
Visibility
37.9mi
UNLIMITED
70 mi0 mi−24h−18h−12h−6hnow
Earth · GOES-19 ABI
Full Disk · Visible · GeoColor
GOES-19 full disk Visible · GeoColor
True-color daytime, blue/IR sandwich at night
18:47 UTC · SeaTac, WA · NOAA NESDIS / STAR · up to 10848 px
Continental US · GOES-19 ABI
CONUS Sector · Visible · GeoColor
GOES-19 CONUS Visible · GeoColor
Daytime true-color, blue-light/IR sandwich at night
18:47 UTC · SeaTac, WA · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
SeaTac, WA
Satellite · infrared · animated
SeaTac, WA
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
SeaTac, WA
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
4:39 AM
Sunrise
10:18 PM
Daylight
15h 50m
Sunset
2:08 PM
Civil dusk
9:50 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
SeaTac, WA
The moon
Waning Gibbous
79% illuminated
Moonrise
11:18 PM
Moonset
10:12 AM
In sign
♓︎ Pisces
SeaTac, WA
Microseason
Jul 1–5

Fireweed Ignites

fish
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

SeaTac at a glance

  • Today vs. normal: 4°F below the seasonal normal for this latitude
  • Last frost: May 31 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

16-Day Forecast — SeaTac

  1. Sat71°56°2%
  2. Sun73°53°0%
  3. Mon85°51°0%
  4. Tue84°52°1%
  5. Wed69°57°10%
  6. Thu78°50°9%
  7. Fri84°51°3%
  8. Sat87°55°9%
  9. Sun90°61°5%
  10. Mon93°59°5%
  11. Tue88°57°5%
  12. Wed79°53°3%
  13. Thu92°55°0%
  14. Fri94°62°3%
  15. Sat98°62°0%
  16. Sun92°64°0%

Forecast data from Open-Meteo (CC BY 4.0).

Right now in the garden

Peak growing season

As of July 4, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.

January 1–5: The Year's Deep Silence.January 6–10: The First Pressure Shift.January 11–15: The Lengthening.January 16–20: The Crows Begin.January 21–25: Skunk Cabbage Wakens.January 26–31: The Fog Deepens.February 1–5: The Sap Stirs.February 6–10: East Wind Weakens the Marine Layer.February 11–15: Thrush Song at First Light.February 16–20: The Salmon Remember.February 21–25: The Soil Awakens.February 26–28: Mist Begins to Linger.March 1–5: The Buds Emerge.March 6–10: The Small Lives Stir.March 11–15: The Spring Salmon Peak.March 16–20: Alder Catkins Dust the Air.March 21–25: Equinox Fog Clears.March 26–31: Salmonberry First Bloom.April 1–5: Thunder Rolls Down the Valleys.April 6–10: Swallows Arrive at the Bridges.April 11–15: Geese Turn Their Faces North.April 16–20: Rainbows Arc Above the Cascades.April 21–25: Reeds Rise from the Wetlands.April 26–30: Frost Releases the Garden.May 1–5: Warblers Flood the Canopy.May 6–10: Frogs Sing at Twilight.May 11–15: Earthworms Rise to Feed the Forest.May 16–20: Shoots and Sprouts Rise in Ranks.May 21–25: Silkworm Days—Full Canopy.May 26–31: Safflower Days—Late May Blooms.June 1–5: Rufous Hummingbirds Arrive.June 6–10: Oceanspray Towers.June 11–15: Solstice Light Crests.June 16–20: Thimbleberry Sweetens.June 21–25: Summer Solstice Stillness.June 26–30: Dry Pattern Deepens.July 1–5: Fireweed Ignites.July 6–10: Peak Hummingbird Wars.July 11–15: Red Huckleberry Ripens.July 16–20: Smoke Season Beckons.July 21–25: Dog Days Hold.July 26–31: Smoke Deepens.August 1–5: August Arrives Dimmed.August 6–10: Cool Wind Hints Return.August 11–15: Cicadas Crescendo.August 16–20: Marine layer deepens.August 21–25: First sweater morning.August 26–31: August snap arrives.September 1–5: Rivers quicken with silver.September 6–10: Dew settles thick.September 11–15: Raptors funnel through passes.September 16–20: Equinox—darkness gains.September 21–25: Fog locks the valleys.September 26–30: Geese stage southward.October 1–5: Mushroom flush deepens.October 6–10: Maples ignite orange.October 11–15: Frost's first mark.October 16–20: Oaks turn russet.October 21–25: First killing frost.October 26–31: Atmospheric rivers arrive.November 1–5: Maple and ivy turn to amber.November 6–10: Last leaves cling in quiet rain.November 11–15: First frost finds the lowlands.November 16–20: Bare branches open the winter sky.November 21–25: Heavy rains mask the stars.November 26–30: North wind clears the gloom.December 1–5: Darkness settles early.December 6–10: Winter cold locks the sky.December 11–15: The days reach their minimum.December 16–20: Ice forms at the margins.December 21–25: The sun turns at solstice.December 26–31: Year's end in silence.🌱February 14 — First skunk-cabbage spathes thaw their way up☀️March 20 — Spring equinox — day and night balance🌸April 5 — Cherry blossoms peak in the parks🐦May 10 — Warbler migration peaks along the coast✨May 25 — First fireflies scout the meadows at dusk🌞June 21 — Summer solstice — longest day🦗July 25 — Peak cicada chorus in the afternoons🌊August 18 — Warmest sea-surface temperatures of the year🍂September 22 — Autumn equinox — the slow turn❄️October 25 — First widespread frost in the suburbs🍁November 10 — Peak leaf color across the Hudson Valley🌙December 21 — Winter solstice — longest night

Microseason · July 1–5

Fireweed Ignites

Magenta fireweed spires surge from burned and cleared slopes, their blooms climbing from base upward. July's signature color claims the disturbed ground.

Day 185 of 365 · Wedge 37 of 72

The solar year drawn as a wheel of 72 five-day windows. Each wedge is one microseason; the four colored arcs mark winter, spring, summer, and autumn; the small icons sit at notable phenological events. The crimson pointer creeps clockwise as the year turns.

Planting calendar

MonthPlantHarvest
January——
February——
March——
April——
Maylettuce, peas, spinach, radisheslettuce, peas, radishes
Junelettuce, peas, spinach, radishes, tomatoes, peppers, beans, squashlettuce, peas, radishes
Julytomatoes, peppers, beans, squashtomatoes, beans, summer squash
Augusttomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
Septemberfall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
October—winter squash, tomatoes (last)
November——
December——

A year in weather

August is SeaTac's warmest stretch (~67°F) and January its coldest (~38°F); precipitation crests in November at 7.9 inches and ebbs in July to 0.5 inches.

MonthMean tempPrecipRainy days
January38°7.5″23
February40°5.5″20
March43°5.6″23
April48°4.1″20
May55°3.1″19
June60°2.4″16
July66°0.5″7
August67°0.9″6
September60°2.4″12
October51°6.2″19
November44°7.9″23
December38°7.5″24

Regional context

Drawing on NOAA NCEI 1991-2020 normals, SeaTac's January averages 38°F and July 66°F — 28°F apart — while precipitation totals roughly 53.6 inches over some 211 days.

SeaTac's moisture rides winter storm tracks: November brings 7.9 inches over 22.6 wet days, while July sees only 0.5 inches across 6.8 days in the dry warm season. It is a winter-storm rhythm SeaTac shares with places like Normandy Park, WA, Tukwila, WA and Burien, WA.

By late-May the frosts ease in SeaTac, opening the season for peas, lettuce, spinach, and radishes. Hold SeaTac's tender crops — tomatoes, peppers, basil — until 10-14 days past SeaTac's last frost. Around early-October, freezing nights resume in SeaTac and tender crops must come in. In SeaTac, low spots run 4-7°F colder than nearby slopes, nudging SeaTac's frost dates a week.

Similar climates: Normandy Park, WA, Tukwila, WA, Burien, WA, Des Moines, WA, Bryn Mawr-Skyway, WA.

Frequently asked

When does it freeze in SeaTac?
SeaTac's last spring frost lands near mid-May, and in SeaTac the first fall frost follows around mid-October.
What is the rainy season in SeaTac?
SeaTac sees its heaviest rain in November (around 7.9 inches), part of roughly 54 inches a year.
What is the warmest month in SeaTac?
On average August tops the year in SeaTac at about 67°F.
What is the coldest month in SeaTac?
The coldest stretch in SeaTac falls in January, around 38°F on average.
When can I start a vegetable garden in SeaTac?
Around mid-May, start frost-hardy crops in SeaTac; tomatoes and basil belong a fortnight later.
How many rainy days does SeaTac get?
SeaTac averages about 211 days with measurable rain or snow each year.
What hardiness zone is SeaTac?
With January around 38°F, SeaTac's zone reflects that minimum — the USDA ZIP map confirms SeaTac's band.
What is the 10-day forecast for SeaTac?
SeaTac's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
Will it rain this week in SeaTac?
See this week's day-by-day rain chances for SeaTac in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in SeaTac?
Current conditions for SeaTac and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the SeaTac forecast updated?
The SeaTac forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in SeaTac?
Today's sunrise and sunset times for SeaTac are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
How accurate is the weather forecast for SeaTac?
The next few days in SeaTac's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

In SeaTac, Washington, the warm-summer Mediterranean climate runs from about 38°F in January to 66°F in July, a 28°F seasonal range.

In a typical year SeaTac records about 54 inches of precipitation on around 211 days.

SeaTac's 28°F range, set by its 47.4°N position, drives frost timing and what thrives in SeaTac.

All cities in Washington →

Seattle, WA weather →

ZIP codes in SeaTac

  • 98158
  • 98148
  • 98198
  • 98168
  • 98188
  • 98131

Climate normals from the Open-Meteo Climate API. Köppen approximation from NOAA NCEI U.S. Climate Regions. See methodology for data sources, editorial rules, and corrections. Maintainer: Brian Tighe.