Keizer, Oregon Weather
Rufous Hummingbirds Arrive. Day 76 of spring. Read this microseason across nine climate regions →
Keizer weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 3Light Drizzle23%0.01″72°51°—
- ThursdayJun 4Overcast——69°46°-3°
- FridayJun 5Light Drizzle——64°42°-5°
- SaturdayJun 6Drizzle42%—61°43°-3°
- SundayJun 7Overcast——68°40°+7°
- MondayJun 8Drizzle37%0.11″54°47°-14°
- TuesdayJun 9Overcast32%—63°47°+9°
PM2.5/PM10 ratio 0.60 with 8 mph wind — characteristic of long-range haze transport rather than a local source. AQI flat over the last 6 hours (within ±3 points).
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 42. Overcast through the UV peak window (cloud cover ~62%) — afternoon ozone should stay flat.
- Present
- AQI 42
- UV peak
- 5.7 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 16
PM × Wind × Precip
PM2.5/PM10 ratio 0.60 with 8 mph wind — characteristic of long-range haze transport rather than a local source.
- PM2.5/PM10
- 0.60
- Wind
- light
- 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).
The higher the clouds, the finer the weather.
- Moonrise
- 6:29 AM
- Moonset
- 2:57 PM
- In sign
- ♑︎ Capricorn
Rufous Hummingbirds Arrive
Keizer at a glance
- Today vs. normal: 68°F — typical for the season
- Last frost: May 16 (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 3, 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.
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
Keizer's warmest month is July (~69°F mean) and its coldest is December (~41°F). Rainfall peaks in December (7.0 inches) and bottoms out in July (0.3 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 42° | 6.1″ | 13 |
| February | 44° | 4.5″ | 10 |
| March | 48° | 4.3″ | 11 |
| April | 51° | 3.1″ | 10 |
| May | 58° | 2.3″ | 6 |
| June | 63° | 1.3″ | 4 |
| July | 69° | 0.3″ | 1 |
| August | 69° | 0.4″ | 1 |
| September | 64° | 1.5″ | 3 |
| October | 54° | 3.5″ | 7 |
| November | 46° | 6.0″ | 12 |
| December | 41° | 7.0″ | 13 |
Regional context
Keizer 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 Keizer?
- Keizer's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in Keizer?
- December is the wettest month with about 7.0 inches of rain on average; the city receives roughly 40 inches annually.
- What is the warmest month in Keizer?
- July is typically warmest, averaging about 69°F.
- What is the coldest month in Keizer?
- December is typically coldest, averaging about 41°F.
- When can I start a vegetable garden in Keizer?
- 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 Keizer get?
- Keizer averages about 91 rainy days per year.
- What hardiness zone is Keizer?
- Keizer'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
Keizer, 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, Keizer receives about 40 inches of precipitation spread over roughly 91 rainy days.
The rhythm of the year is set by latitude (45.0°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.