Weather in Richland, Washington
High country wildflowers peak. Day 58 of spring. Read this microseason across nine climate regions →
- TodayMay 16Overcast—66°49°
- SundayMay 17Light Drizzle—70°45°
- MondayMay 18Overcast—73°50°
- TuesdayMay 19Overcast—75°50°
- WednesdayMay 20Overcast—77°49°
- ThursdayMay 21Overcast—84°52°
- FridayMay 22Overcast—86°58°
- PM 2.5
- 1.1 μg/m³
- PM 10
- 1.5 μg/m³
- NO₂
- 0.5 μg/m³
- Ozone
- 96.0 μg/m³
- UV Index
- 1.9 Low
Flowers blooming in late autumn, a sure sign of a bad winter coming.
- Moonrise
- 11:44 AM
- Moonset
- 2:46 AM
- In sign
- ♉︎ Taurus
High country wildflowers peak
Richland at a glance
- Today vs. normal: 66°F — typical for the season
- Last frost: May 24 (climatological average for this latitude)
- Microseason: 28 of 72, May 16–20
- Planting window: Direct sow okra, melons, and southern peas. Thin carrot rows.
Right now in the garden
Cool-season window is open
As of May 16, the cool-season window is open or about to open. Direct-sow peas, lettuce, spinach, radishes, and brassicas now. Hold off on warm-season crops until 1–2 weeks after the last spring frost (around May).
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
Richland's warmest month is July (~77°F mean) and its coldest is January (~36°F). Rainfall peaks in January (1.1 inches) and bottoms out in August (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
Richland 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 Richland?
- Richland's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in Richland?
- January is the wettest month with about 1.1 inches of rain on average; the city receives roughly 8 inches annually.
- What is the warmest month in Richland?
- July is typically warmest, averaging about 77°F.
- What is the coldest month in Richland?
- January is typically coldest, averaging about 36°F.
- When can I start a vegetable garden in Richland?
- 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 Richland get?
- Richland averages about 27 rainy days per year.
- What hardiness zone is Richland?
- Richland'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
Richland, Washington sits in a warm-summer Mediterranean climate zone. January means hover near 36°F while July averages 77°F — a 41°F seasonal swing.
Across the year, Richland receives about 8 inches of precipitation spread over roughly 27 rainy days.
The rhythm of the year is set by latitude (46.3°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.