Weather in Meridian, Idaho
High country wildflowers peak. Day 59 of spring. Read this microseason across nine climate regions →
When the dew is on the grass, rain will never come to pass.
- Moonrise
- 12:24 PM
- Moonset
- 3:45 AM
- In sign
- ♉︎ Taurus
High country wildflowers peak
Meridian at a glance
- Today vs. normal: NaN°F below the seasonal normal for this latitude
- Last frost: May 8 (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 17, 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
Meridian's warmest month is July (~75°F mean) and its coldest is January (~31°F). Rainfall peaks in December (1.4 inches) and bottoms out in August (0.2 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 31° | 1.4″ | 5 |
| February | 37° | 1.0″ | 4 |
| March | 45° | 1.3″ | 4 |
| April | 50° | 1.1″ | 4 |
| May | 59° | 1.4″ | 4 |
| June | 67° | 0.7″ | 2 |
| July | 75° | 0.3″ | 1 |
| August | 74° | 0.2″ | 1 |
| September | 64° | 0.4″ | 1 |
| October | 52° | 0.8″ | 3 |
| November | 40° | 1.2″ | 4 |
| December | 31° | 1.4″ | 5 |
Regional context
Meridian belongs to a warm-summer Mediterranean climate region — a cohort of cities with comparable temperature ranges, seasonal patterns, and growing conditions.
Similar climates: Boise, ID, Nampa, ID, Coeur d'Alene, ID, Caldwell, ID, Post Falls, ID.
Naturalist notes
By late May, western tanagers return to the cottonwood corridors along the Boise River, their breeding song carrying through the lengthening evenings.
Common lilac leaf-out is well underway by mid-May, a phenological marker that often aligns with the last spring frost in this part of the Treasure Valley.
Frequently asked
- When does it freeze in Meridian?
- Meridian's last spring frost typically falls around mid-May, and the first fall frost arrives around mid-October.
- What is the rainy season in Meridian?
- December is the wettest month with about 1.4 inches of rain on average; the city receives roughly 11 inches annually.
- What is the warmest month in Meridian?
- July is typically warmest, averaging about 75°F.
- What is the coldest month in Meridian?
- January is typically coldest, averaging about 31°F.
- When can I start a vegetable garden in Meridian?
- 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 Meridian get?
- Meridian averages about 37 rainy days per year.
- What hardiness zone is Meridian?
- Meridian'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
Meridian, Idaho has a warm-summer Mediterranean climate. January averages 31°F and July averages 75°F — a 44°F swing between seasons.
The city receives about 11 inches of precipitation spread over roughly 37 rainy days per year.
Latitude (43.6°N), distance from large water bodies, and elevation all set the rhythm of the year — shaping what grows, when frost arrives, and how daily weather unfolds.