Meridian, Idaho Weather
Thunder retreats as the monsoon dies. Day 93 of summer. Read this microseason across nine climate regions →
Meridian weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 12:10 AM MDT · Open-Meteo
- TodaySep 21Clear——85°54°—
- TuesdaySep 22Overcast——86°55°+1°
- WednesdaySep 23Overcast——88°58°+2°
- ThursdaySep 24Overcast——94°62°+6°
- FridaySep 25Overcast14%—75°55°-19°
- SaturdaySep 26Overcast14%—76°45°+1°
- SundaySep 27Overcast——82°55°+6°
Air quality now AQI 39 · Good
AQI 39 (Good), driven by PM2.5. AQI flat over the last 6 hours (within ±3 points). PM2.5 at 4.9 µg/m³ (AQI 27) with a 0.96 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in stagnant air, not road dust.
OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.
What's driving it
PM × Wind × Precip
PM2.5 at 4.9 µg/m³ (AQI 27) with a 0.96 fine-to-coarse ratio and 5 mph wind — combustion smoke trapped in stagnant air, not road dust.
- PM2.5/PM10
- 0.96
- Wind
- light
- Recent rain
- 0h in last 6h
- Pattern
- stagnant smoke
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).
September dries up ditches or breaks down bridges.
- Moonrise
- 5:32 PM
- Moonset
- 1:59 AM
- In sign
- ♑︎ Capricorn
Thunder retreats as the monsoon dies
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Meridian at a glance
- Today vs. normal: Today averages 70°F (high 85°F, low 54°F), 9°F above the 61°F normal for Sep 21
- Last frost: April 24 (1991–2020 median, NOAA station 14 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash
15-Day Forecast — Meridian
- Mon85°54°1%
- Tue86°55°2%
- Wed88°58°0%
- Thu94°62°1%
- Fri75°55°14%
- Sat76°45°14%
- Sun82°55°3%
- Mon76°48°3%
- Tue86°54°6%
- Wed82°62°6%
- Thu81°60°3%
- Fri86°63°3%
- Sat71°45°6%
- Sun64°41°6%
- Mon73°47°3%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Meridian
Interactive wind and temperature map centered on Meridian — it loads in your browser. Open the full weather map.
Right now in the garden
Fall planting + final harvests
As of September 21, the season's first frost (typically October 21) is approaching. Pick what frost-tender plants still carry before the next cold front. This city's planting calendar for September: plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, and winter squash.
SPC Convective Outlook
Storm Prediction Center — Meridian
SPC includes Meridian in the general thunderstorm area tomorrow — no severe risk, but storms are possible.
- TODAYNONENo severe risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3NONENo severe risk
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
Source: NOAA / NWS Storm Prediction Center categorical convective outlook.
Sun & seasons in Meridian
Meridian sits in Ada County, where the year’s longest day runs 15h 26m of daylight and its shortest just 8h 56m — a swing of +6h 30m between the June and December solstices. Clocks spring forward on Sunday, March 8, 2026 and fall back on Sunday, November 1, 2026.
Boise, the state’s largest city, lies about 8 miles to the E. The nearest town Meridian tracks is Boise, roughly 8 miles to the E.
Air quality in Meridian
Air quality in Meridian’s county has trended cleaner since 2020; its cleanest year on record was 2025 (median AQI 42). See the full air-quality history for Meridian.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| April | lettuce, peas, spinach, radishes | radishes |
| May | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, spinach, radishes |
| June | tomatoes, peppers, beans, squash | lettuce, peas, spinach, radishes |
| July | tomatoes, peppers, beans, squash | lettuce, peas, spinach, beans, summer squash, garlic |
| August | beans, squash, fall brassicas, carrots | tomatoes, peppers, beans, summer squash |
| September | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash |
| October | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
| November | — | fall brassicas, carrots |
A year in weather
The year in Meridian tops out in July (~75°F) and dips lowest in January (~31°F), with December wettest at 1.4 inches and August driest at 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
Similar climates Garden City, ID, Eagle, ID, Star, ID
Drawing on NOAA NCEI 1991-2020 normals, Meridian's January averages 31°F and July 75°F — 44°F apart — while precipitation totals roughly 11 inches over some 37 days.
Precipitation in Meridian peaks in the cool season: December averages 1.4 inches across 4.7 storm-fed days, while August bottoms out at 0.2 inches over just 0.7 rainy days. It is a winter-storm rhythm Meridian shares with places like Garden City, ID, Eagle, ID and Star, ID.
The cool-season window in Meridian starts at April 24, when nights stop freezing — think peas, lettuce, spinach, and radishes. In Meridian, warm-season transplants — tomatoes, peppers, basil — wait two weeks past Meridian's frost date. Around October 21, freezing nights resume in Meridian and tender crops must come in. In about half of years, Meridian's last freeze comes after April 24.
Similar climates: Garden City, ID, Eagle, ID, Star, ID, Boise, ID, Nampa, ID.
Frequently asked
- When does it freeze in Meridian?
- In Meridian, expect the last spring frost near April 24; Meridian's first autumn frost comes around October 21.
- What is the rainy season in Meridian?
- Meridian sees its heaviest rain in December (around 1.4 inches), part of roughly 11 inches a year.
- What is the warmest month in Meridian?
- July is Meridian's warmest month, averaging about 75°F.
- What is the coldest month in Meridian?
- Meridian bottoms out in January, with a mean near 31°F.
- When can I start a vegetable garden in Meridian?
- Meridian's last frost (April 24) cues hardy greens; in Meridian, hold heat-lovers two weeks past.
- How many rainy days does Meridian get?
- Meridian records around 37 days of measurable precipitation annually.
- What hardiness zone is Meridian?
- Meridian's USDA zone comes from its January mean (31°F); enter the ZIP on the USDA lookup for the number.
- What is the 10-day forecast for Meridian?
- Meridian's extended outlook — daily high and low temperatures and precipitation chances for each upcoming day — is in the daily forecast above.
- Will it rain this week in Meridian?
- See this week's day-by-day rain chances for Meridian in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Meridian?
- Current conditions for Meridian and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Meridian forecast updated?
- The Meridian forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Meridian?
- Today's sunrise and sunset times for Meridian are in the Almanac section above, along with civil dawn, civil dusk, and day length. Day length is longest near the summer solstice and shortest near the winter solstice.
- How accurate is the weather forecast for Meridian?
- The next few days in Meridian's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Meridian sits at 43.6°N; its climate zone is warm-summer Mediterranean (Köppen approximation).
ZIP codes in Meridian
- 83642
- 83646
- 83680