Newcastle, Washington Weather
Rufous Hummingbirds Arrive. Day 77 of spring. Read this microseason across nine climate regions →
Newcastle weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Overcast——66°54°—
- FridayJun 5Rain32%0.11″59°49°-7°
- SaturdayJun 6Heavy Drizzle81%0.02″54°47°-5°
- SundayJun 7Light Drizzle——64°45°+10°
- MondayJun 8Overcast54%—72°42°+8°
- TuesdayJun 9Light Drizzle54%—77°51°+5°
- WednesdayJun 10Overcast33%—75°48°-2°
Ozone at AQI 40. AQI down 5 over the last 6 hours (steady decline since this morning). Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
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. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 40
- UV peak
- 6.6 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 18
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
- 7:08 AM
- Moonset
- 3:50 PM
- In sign
- ♒︎ Aquarius
Rufous Hummingbirds Arrive
Newcastle at a glance
- Today vs. normal: 5°F below the seasonal normal for this latitude
- Last frost: May 31 (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 — Newcastle
SPC has placed Newcastle in the General Thunderstorms category for severe thunderstorms tomorrow.
- TODAYNONENo severe risk
- TOMORROWTSTMGeneral Thunderstorms
- 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
Newcastle's warmest month is August (~67°F mean) and its coldest is December (~42°F). Rainfall peaks in November (5.8 inches) and bottoms out in July (0.8 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 42° | 5.1″ | 12 |
| February | 43° | 3.5″ | 9 |
| March | 47° | 3.9″ | 11 |
| April | 51° | 3.0″ | 9 |
| May | 57° | 2.2″ | 6 |
| June | 61° | 1.6″ | 5 |
| July | 67° | 0.8″ | 2 |
| August | 67° | 1.0″ | 3 |
| September | 62° | 1.7″ | 5 |
| October | 54° | 3.6″ | 9 |
| November | 46° | 5.8″ | 12 |
| December | 42° | 5.5″ | 12 |
Regional context
Newcastle 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 Newcastle?
- Newcastle's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in Newcastle?
- November is the wettest month with about 5.8 inches of rain on average; the city receives roughly 38 inches annually.
- What is the warmest month in Newcastle?
- August is typically warmest, averaging about 67°F.
- What is the coldest month in Newcastle?
- December is typically coldest, averaging about 42°F.
- When can I start a vegetable garden in Newcastle?
- 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 Newcastle get?
- Newcastle averages about 95 rainy days per year.
- What hardiness zone is Newcastle?
- Newcastle'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
Newcastle, Washington sits in a warm-summer Mediterranean climate zone. January means hover near 42°F while July averages 67°F — a 24°F seasonal swing.
Across the year, Newcastle receives about 38 inches of precipitation spread over roughly 95 rainy days.
The rhythm of the year is set by latitude (47.5°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.