West Haven-Sylvan, Oregon Weather
Rufous Hummingbirds Arrive. Day 77 of spring. Read this microseason across nine climate regions →
West Haven-Sylvan weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——66°50°—
- FridayJun 5Drizzle17%0.03″57°47°-9°
- SaturdayJun 6Drizzle80%—60°46°+3°
- SundayJun 7Overcast10%—70°42°+10°
- MondayJun 8Light Drizzle55%0.06″61°50°-9°
- TuesdayJun 9Light Drizzle55%0.04″69°50°+8°
- WednesdayJun 10Mostly Clear39%—77°48°+8°
Ozone at AQI 40 now. AQI flat over the last 6 hours (within ±3 points). With UV 7.3 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 28 by mid-afternoon.
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 40 now. With UV 7.3 peaking around 1 PM under partly cloudy skies, surface ozone likely climbs to AQI 28 by mid-afternoon.
- Present
- AQI 40
- UV peak
- 7.3 at 1 PM
- Sky at peak
- partly cloudy
- Projected peak
- AQI 28
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
- 7:02 AM
- Moonset
- 4:01 PM
- In sign
- ♒︎ Aquarius
Rufous Hummingbirds Arrive
West Haven-Sylvan at a glance
- Today vs. normal: 6°F below the seasonal normal for this latitude
- Last frost: May 19 (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 — West Haven-Sylvan
SPC has placed West Haven-Sylvan 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
West Haven-Sylvan's warmest month is August (~70°F mean) and its coldest is December (~42°F). Rainfall peaks in December (7.3 inches) and bottoms out in July (0.4 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 42° | 6.4″ | 14 |
| February | 45° | 4.7″ | 10 |
| March | 48° | 4.8″ | 12 |
| April | 53° | 3.6″ | 11 |
| May | 59° | 2.6″ | 8 |
| June | 63° | 1.5″ | 5 |
| July | 69° | 0.4″ | 2 |
| August | 70° | 0.5″ | 2 |
| September | 65° | 1.6″ | 4 |
| October | 55° | 4.0″ | 9 |
| November | 47° | 6.6″ | 13 |
| December | 42° | 7.3″ | 14 |
Regional context
West Haven-Sylvan 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: Portland, OR, Eugene, OR, Salem, OR, Medford, OR, Bend, OR.
Frequently asked
- When does it freeze in West Haven-Sylvan?
- West Haven-Sylvan's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in West Haven-Sylvan?
- December is the wettest month with about 7.3 inches of rain on average; the city receives roughly 44 inches annually.
- What is the warmest month in West Haven-Sylvan?
- August is typically warmest, averaging about 70°F.
- What is the coldest month in West Haven-Sylvan?
- December is typically coldest, averaging about 42°F.
- When can I start a vegetable garden in West Haven-Sylvan?
- 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 West Haven-Sylvan get?
- West Haven-Sylvan averages about 102 rainy days per year.
- What hardiness zone is West Haven-Sylvan?
- West Haven-Sylvan'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
West Haven-Sylvan, Oregon sits in a warm-summer Mediterranean climate zone. January means hover near 42°F while July averages 69°F — a 27°F seasonal swing.
Across the year, West Haven-Sylvan receives about 44 inches of precipitation spread over roughly 102 rainy days.
The rhythm of the year is set by latitude (45.5°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.