Steilacoom, Washington Weather
Rufous Hummingbirds Arrive. Day 77 of spring. Read this microseason across nine climate regions →
Steilacoom weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Overcast11%—70°57°—
- ThursdayJun 4Overcast——64°51°-6°
- FridayJun 5Drizzle78%0.03″58°46°-6°
- SaturdayJun 6Light Showers80%0.09″57°43°-1°
- SundayJun 7Light Drizzle——66°40°+9°
- MondayJun 8Light Rain59%0.27″56°47°-10°
- TuesdayJun 9Light Drizzle43%0.01″59°48°+3°
Ozone at AQI 37 — peak already passed at 1 PM under overcast skies. AQI flat over the last 6 hours (within ±3 points). Levels should ease through evening.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
Ozone × UV × Sky
Ozone at AQI 37 — peak already passed at 1 PM under overcast skies. Levels should ease through evening.
- Present
- AQI 37
- UV peak
- 0.7 at earlier today
- Sky at peak
- overcast
- Projected peak
- AQI 37
PM × Wind × Precip
PM2.5/PM10 ratio 0.67 with 10 mph wind — characteristic of long-range haze transport rather than a local source.
- PM2.5/PM10
- 0.67
- Wind
- breezy
- Recent rain
- 0h in last 6h
- Pattern
- transport
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).
A summer fog for fair, a winter fog for rain.
- Moonrise
- 7:09 AM
- Moonset
- 3:53 PM
- In sign
- ♑︎ Capricorn
Rufous Hummingbirds Arrive
Steilacoom at a glance
- Today vs. normal: 67°F — typical for the season
- Last frost: May 29 (climatological average for this latitude)
- Microseason: Jun 1–5
- Planting window: Harvest spring lettuce before it bolts. Sow heat-tolerant greens.
Right now in the garden
Peak growing season
As of June 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.
SPC Convective Outlook
Storm Prediction Center — Steilacoom
SPC has placed Steilacoom in the General Thunderstorms category for severe thunderstorms day after tomorrow.
- TODAYNONENo severe risk
- TOMORROWNONENo severe risk
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.
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
Steilacoom's warmest month is July (~67°F mean) and its coldest is December (~42°F). Rainfall peaks in November (6.5 inches) and bottoms out in July (0.6 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 43° | 6.0″ | 13 |
| February | 44° | 4.0″ | 10 |
| March | 47° | 4.4″ | 12 |
| April | 52° | 3.4″ | 9 |
| May | 58° | 2.0″ | 6 |
| June | 62° | 1.4″ | 4 |
| July | 67° | 0.6″ | 2 |
| August | 67° | 0.8″ | 2 |
| September | 62° | 1.6″ | 4 |
| October | 54° | 4.1″ | 9 |
| November | 47° | 6.5″ | 13 |
| December | 42° | 6.0″ | 14 |
Regional context
Steilacoom sits within a warm-summer Mediterranean climate region — a cohort that shares similar temperature ranges, seasonal patterns, and growing conditions across nearby cities.
Similar climates: Seattle, WA, Spokane, WA, Kennewick, WA, Bremerton, WA, Tacoma, WA.
Frequently asked
- When does it freeze in Steilacoom?
- Steilacoom's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in Steilacoom?
- November is the wettest month with about 6.5 inches of rain on average; the city receives roughly 41 inches annually.
- What is the warmest month in Steilacoom?
- July is typically warmest, averaging about 67°F.
- What is the coldest month in Steilacoom?
- December is typically coldest, averaging about 42°F.
- When can I start a vegetable garden in Steilacoom?
- Cool-season crops (peas, lettuce) can be sown around the last spring frost (mid-May); warm-season crops (tomatoes, peppers) wait until 1–2 weeks after.
- How many rainy days does Steilacoom get?
- Steilacoom averages about 96 rainy days per year.
- What hardiness zone is Steilacoom?
- Steilacoom's USDA hardiness zone is determined by its lowest average winter temperature; check the USDA's online lookup with the city ZIP for the current zone designation.
Climate
Steilacoom, Washington sits in a warm-summer Mediterranean climate zone. January means hover near 43°F while July averages 67°F — a 24°F seasonal swing.
Across the year, Steilacoom receives about 41 inches of precipitation spread over roughly 96 rainy days.
The rhythm of the year is set by latitude (47.2°N), proximity to large water bodies, and elevation — all of which shape what grows here, when frost is likely, and what the weather story looks like day to day.