West Haven-Sylvan, Oregon Weather
Fireweed Ignites. Day 14 of summer. Read this microseason across nine climate regions →
West Haven-Sylvan weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Overcast——72°54°—
- SundayJul 5Overcast——76°51°+4°
- MondayJul 6Overcast——86°53°+10°
- TuesdayJul 7Overcast——85°56°-1°
- WednesdayJul 8Overcast——75°57°-10°
- ThursdayJul 9Clear——81°53°+6°
- FridayJul 10Clear——85°53°+4°
AQI 24 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 6.7 µg/m³ (AQI 37) with a 0.84 fine-to-coarse ratio and 4 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.
What's driving it
PM × Wind × Precip
PM2.5 at 6.7 µg/m³ (AQI 37) with a 0.84 fine-to-coarse ratio and 4 mph wind — combustion smoke trapped in calm air, not road dust.
- PM2.5/PM10
- 0.84
- Wind
- calm
- 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).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 11:16 PM
- Moonset
- 10:16 AM
- In sign
- ♓︎ Pisces
Fireweed Ignites
West Haven-Sylvan at a glance
- Today vs. normal: 9°F below the seasonal normal for this latitude
- Last frost: May 19 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
16-Day Forecast — West Haven-Sylvan
- Sat72°54°1%
- Sun76°51°0%
- Mon86°53°0%
- Tue85°56°1%
- Wed75°57°2%
- Thu81°53°0%
- Fri85°53°0%
- Sat79°58°6%
- Sun79°54°3%
- Mon77°51°4%
- Tue90°50°2%
- Wed99°59°3%
- Thu98°69°3%
- Fri103°69°3%
- Sat96°69°3%
- Sun97°66°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.
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
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
In West Haven-Sylvan, August runs warmest near 69°F and January coldest around 39°F, while December is the wettest month (7.2 inches) and July the driest (0.3 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 39° | 7.2″ | 23 |
| February | 41° | 5.5″ | 19 |
| March | 44° | 5.9″ | 22 |
| April | 50° | 3.9″ | 19 |
| May | 56° | 2.7″ | 17 |
| June | 62° | 1.7″ | 13 |
| July | 68° | 0.3″ | 4 |
| August | 69° | 0.5″ | 5 |
| September | 63° | 1.9″ | 10 |
| October | 53° | 5.7″ | 17 |
| November | 45° | 7.1″ | 21 |
| December | 39° | 7.2″ | 22 |
Regional context
Drawing on NOAA NCEI 1991-2020 normals, West Haven-Sylvan's January averages 39°F and July 68°F — 29°F apart — while precipitation totals roughly 49.7 inches over some 192 days.
Precipitation in West Haven-Sylvan peaks in the cool season: December averages 7.2 inches across 21.9 storm-fed days, while July bottoms out at 0.3 inches over just 4.2 rainy days. That groups West Haven-Sylvan with places like West Slope, OR, Cedar Hills, OR and Cedar Mill, OR on the same cool-season storm track.
By late-May the frosts ease in West Haven-Sylvan, opening the season for peas, lettuce, spinach, and radishes. Hold West Haven-Sylvan's tender crops — tomatoes, peppers, basil — until 10-14 days past West Haven-Sylvan's last frost. West Haven-Sylvan's window closes around early-October as overnight lows return below freezing. Within West Haven-Sylvan, cold-air pooling chills low spots by 5-10°F, shifting West Haven-Sylvan's local frost dates.
Similar climates: West Slope, OR, Cedar Hills, OR, Cedar Mill, OR, Raleigh Hills, OR, Marlene Village, OR.
Frequently asked
- When does it freeze in West Haven-Sylvan?
- Frost typically leaves West Haven-Sylvan by mid-May and returns to West Haven-Sylvan near mid-October.
- What is the rainy season in West Haven-Sylvan?
- December is the wettest month in West Haven-Sylvan, about 7.2 inches on average; the year totals roughly 50 inches.
- What is the warmest month in West Haven-Sylvan?
- The warmest stretch in West Haven-Sylvan comes in August, around 69°F on average.
- What is the coldest month in West Haven-Sylvan?
- On average January is the chilliest month in West Haven-Sylvan, about 39°F.
- When can I start a vegetable garden in West Haven-Sylvan?
- Frost-hardy sowings begin at mid-May in West Haven-Sylvan; warm-season starts follow two weeks on.
- How many rainy days does West Haven-Sylvan get?
- West Haven-Sylvan averages about 192 days with measurable rain or snow each year.
- What hardiness zone is West Haven-Sylvan?
- West Haven-Sylvan sits in the USDA zone set by January lows near 39°F; the USDA ZIP tool gives the band.
- What is the 10-day forecast for West Haven-Sylvan?
- West Haven-Sylvan'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 West Haven-Sylvan?
- See this week's day-by-day rain chances for West Haven-Sylvan in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in West Haven-Sylvan?
- Current conditions for West Haven-Sylvan and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the West Haven-Sylvan forecast updated?
- The West Haven-Sylvan forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in West Haven-Sylvan?
- Today's sunrise and sunset times for West Haven-Sylvan 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 West Haven-Sylvan?
- The next few days in West Haven-Sylvan's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
West Haven-Sylvan, Oregon has a warm-summer Mediterranean climate: January averages roughly 39°F, July about 68°F, 29°F between them.
Yearly precipitation in West Haven-Sylvan totals around 50 inches, spread over about 192 days of rain or snow.
At 45.5°N, West Haven-Sylvan's 29°F summer-to-winter swing sets when West Haven-Sylvan's gardens wake and when frost returns.
ZIP codes in West Haven-Sylvan
- 97225
- 97229