Kennewick, Washington Weather
Pikas hayfeeding in granite peaks. Day 77 of spring. Read this microseason across nine climate regions →
Kennewick weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 4Mostly Clear——80°57°—
- FridayJun 5Overcast——74°57°-6°
- SaturdayJun 6Overcast——70°51°-4°
- SundayJun 7Overcast——74°46°+4°
- MondayJun 8Light Drizzle——75°54°+1°
- TuesdayJun 9Light Drizzle20%0.01″68°53°-7°
- WednesdayJun 10Light Drizzle16%0.09″63°50°-5°
Ozone at AQI 35 now. AQI down 8 over the last 6 hours (steady decline since this morning). With UV 7.1 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 33 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 35 now. With UV 7.1 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 33 by mid-afternoon.
- Present
- AQI 35
- UV peak
- 7.1 at 1 PM
- Sky at peak
- clear
- Projected peak
- AQI 33
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
- 6:51 AM
- Moonset
- 3:42 PM
- In sign
- ♒︎ Aquarius
Pikas hayfeeding in granite peaks
Kennewick at a glance
- Today vs. normal: 69°F — typical for the season
- Last frost: May 23 (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
Warm-season window is open
As of June 4, the last spring frost has passed for most years. Transplant tomatoes, peppers, eggplants, basil, and cucurbits (cucumbers, squash, melons) now. Direct-sow beans and corn into warm soil.
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
July brings Kennewick's peak warmth at around 77°F mean temperature, while January delivers the year's coldest conditions at roughly 36°F. Precipitation follows an opposite pattern — January sees the most rainfall at 1.1 inches, and August records the least at 0.2 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 36° | 1.1″ | 4 |
| February | 40° | 0.8″ | 3 |
| March | 47° | 0.7″ | 2 |
| April | 54° | 0.6″ | 2 |
| May | 63° | 0.8″ | 2 |
| June | 69° | 0.6″ | 2 |
| July | 77° | 0.2″ | 1 |
| August | 76° | 0.2″ | 1 |
| September | 67° | 0.3″ | 1 |
| October | 55° | 0.7″ | 2 |
| November | 43° | 0.9″ | 3 |
| December | 36° | 1.1″ | 4 |
Regional context
Kennewick belongs to the warm-summer Mediterranean climate region, sharing temperature ranges, seasonal patterns, and growing conditions with other cities in this climate zone.
Similar climates: Seattle, WA, Spokane, WA, Bremerton, WA, Tacoma, WA, Olympia, WA.
Naturalist notes
Late May brings the peak migration of Western Tanagers through the Columbia River corridor.
Apple orchards throughout the region typically begin their bloom period in early April.
Frequently asked
- When does it freeze in Kennewick?
- Spring's final frost usually occurs around mid-May in Kennewick, while the season's first frost returns around mid-October.
- What is the rainy season in Kennewick?
- January receives the most precipitation, averaging about 1.1 inches, while the city's annual total reaches roughly 8 inches.
- What is the warmest month in Kennewick?
- July typically delivers the year's highest temperatures, averaging about 77°F.
- What is the coldest month in Kennewick?
- January brings the coldest weather, with temperatures averaging about 36°F.
- When can I start a vegetable garden in Kennewick?
- Plant cool-season crops like peas and lettuce around the last spring frost in mid-May, but wait 1–2 weeks longer before planting warm-season varieties like tomatoes and peppers.
- How many rainy days does Kennewick get?
- Kennewick records about 27 rainy days annually on average.
- What hardiness zone is Kennewick?
- Kennewick's USDA hardiness zone depends on average minimum winter temperatures — use the USDA's online zone finder with the city's ZIP code for current zone information.
Climate
Kennewick, Washington experiences a warm-summer Mediterranean climate. January temperatures hover near 36°F while July averages 77°F, creating a 41°F seasonal swing.
Annual precipitation totals about 8 inches, distributed across roughly 27 rainy days throughout the year.
Weather patterns here reflect the city's position at 46.2°N latitude, its proximity to large water bodies, and local elevation. These factors determine growing seasons, frost timing, and daily weather conditions.