SeaTac, Washington Weather
Solstice Light Crests. Day 86 of spring. Read this microseason across nine climate regions →
SeaTac weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 13Clear——81°57°—
- SundayJun 14Overcast——87°63°+6°
- MondayJun 15Overcast——91°61°+4°
- TuesdayJun 16Overcast——78°56°-13°
- WednesdayJun 17Overcast——78°48°0°
- ThursdayJun 18Overcast——80°51°+2°
- FridayJun 19Overcast——83°54°+3°
AQI 45 (Good), driven by PM2.5. AQI up 7 over the last 6 hours (gradual rise). PM2.5 at 18.5 µg/m³, PM10 at 24.4 µg/m³ — typical background levels with no transport signature.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion during the projected peak around 2 PM.
What's driving it
PM × Wind × Precip
PM2.5 at 18.5 µg/m³, PM10 at 24.4 µg/m³ — typical background levels with no transport signature.
- PM2.5/PM10
- 0.76
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- background
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).








































Cut your thistles before St. John, you will have two instead of one.
- Moonrise
- 3:24 AM
- Moonset
- 7:05 PM
- In sign
- ♉︎ Taurus
Solstice Light Crests
SeaTac at a glance
- Today vs. normal: 9°F below the seasonal normal for this latitude
- Last frost: May 31 (climatological average for this latitude)
- Microseason: Jun 11–15
- Planting window: Prune spring-blooming shrubs after flowers fade.
15-Day Forecast — SeaTac
- Sat82°58°0%
- Sun87°63°0%
- Mon91°61°0%
- Tue78°56°4%
- Wed78°48°2%
- Thu80°51°1%
- Fri83°54°2%
- Sat77°51°2%
- Sun80°50°9%
- Mon79°51°3%
- Tue83°52°3%
- Wed89°55°6%
- Thu101°62°13%
- Fri95°64°12%
- Sat86°57°10%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Peak growing season
As of June 13, 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.
Microseason · June 11–15
Solstice Light Crests
The sun barely dips below the horizon. Twilight lingers until nearly midnight; songbirds sing long into dusk, feeding young in the endless glow.
Day 164 of 365 · Wedge 33 of 72
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | — | — |
| May | lettuce, peas, spinach, radishes | lettuce, peas, radishes |
| June | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | tomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, 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.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 38° | 7.5″ | 23 |
| February | 40° | 5.5″ | 20 |
| March | 43° | 5.6″ | 23 |
| April | 48° | 4.1″ | 20 |
| May | 55° | 3.1″ | 19 |
| June | 60° | 2.4″ | 16 |
| July | 66° | 0.5″ | 7 |
| August | 67° | 0.9″ | 6 |
| September | 60° | 2.4″ | 12 |
| October | 51° | 6.2″ | 19 |
| November | 44° | 7.9″ | 23 |
| December | 38° | 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?
- Day length in SeaTac peaks around the June solstice — earliest sunrise and latest sunset — and is shortest near the December 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.
ZIP codes in SeaTac
- 98158
- 98148
- 98198
- 98168
- 98188
- 98131