Nampa, Idaho Weather
Thunder retreats as the monsoon dies. Day 93 of summer. Read this microseason across nine climate regions →
Nampa weather forecast — hour by hour, 7-day outlook, NOAA radar
Conditions updated 1:50 AM MDT · Open-Meteo
- TodaySep 21Clear——85°55°—
- TuesdaySep 22Overcast——86°55°+1°
- WednesdaySep 23Overcast——88°57°+2°
- ThursdaySep 24Overcast——94°65°+6°
- FridaySep 25Overcast12%—75°53°-19°
- SaturdaySep 26Overcast12%—77°46°+2°
- SundaySep 27Overcast——84°57°+7°
Air quality now AQI 36 · Good
AQI 36 (Good), driven by PM2.5. 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.
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
- 2:00 AM
- In sign
- ♑︎ Capricorn
Thunder retreats as the monsoon dies
Read this microseason across nine climate regions →
All 72 microseasons on the year wheel →
Nampa at a glance
- Today vs. normal: Today averages 70°F (high 85°F, low 55°F), 9°F above the 61°F normal for Sep 21
- Last frost: April 29 (1991–2020 median, NOAA station 2 km away)
- Microseason: Sep 21–25
- Planting calendar: September — plant garlic (overwinter); harvest tomatoes, peppers, beans, summer squash, winter squash
15-Day Forecast — Nampa
- Mon85°55°1%
- Tue86°55°2%
- Wed88°57°0%
- Thu94°65°1%
- Fri75°53°12%
- Sat77°46°12%
- Sun84°57°3%
- Mon76°48°3%
- Tue87°51°6%
- Wed83°59°6%
- Thu82°61°5%
- Fri87°61°10%
- Sat72°50°6%
- Sun64°40°6%
- Mon74°45°3%
Forecast data from Open-Meteo (CC BY 4.0).
Live wind & temperature near Nampa
Interactive wind and temperature map centered on Nampa — 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 13) 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 — Nampa
SPC includes Nampa 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 Nampa
Nampa sits in Canyon 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 17 miles to the E. The nearest town Nampa tracks is Meridian, roughly 9 miles to the ENE.
Air quality in Nampa
Air quality in Nampa’s county has trended cleaner since 2020; its cleanest year on record was 2023 (median AQI 34). See the full air-quality history for Nampa.
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| April | lettuce, peas, spinach, 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, fall brassicas, carrots | lettuce, peas, spinach, beans, summer squash, garlic |
| August | — | tomatoes, peppers, beans, summer squash, garlic |
| September | garlic (overwinter) | tomatoes, peppers, beans, summer squash, winter squash |
| October | — | tomatoes, peppers, beans, summer squash, winter squash, fall brassicas, carrots |
| November | — | fall brassicas, carrots |
A year in weather
Nampa peaks at about 75°F in July and bottoms near 31°F in January; December brings the heaviest rain (1.4 inches) and August the least (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 Caldwell, ID, Meridian, ID, Star, ID
Nampa's climate, from NOAA NCEI 1991-2020 station normals, pairs 31°F Januarys with 75°F Julys — a 44°F swing. About 11 inches of precipitation falls over roughly 37 days a year.
Precipitation in Nampa 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. That groups Nampa with places like Caldwell, ID, Meridian, ID and Star, ID on the same cool-season storm track.
The cool-season window in Nampa starts at April 29, when nights stop freezing — think peas, lettuce, spinach, and radishes. In Nampa, warm-season transplants — tomatoes, peppers, basil — wait two weeks past Nampa's frost date. Nampa's window closes around October 13 as Nampa's overnight lows return below freezing. In about half of years, Nampa's last freeze comes after April 29.
Similar climates: Caldwell, ID, Meridian, ID, Star, ID, Middleton, ID, Kuna, ID.
Frequently asked
- When does it freeze in Nampa?
- Nampa's last spring frost lands near April 29, and in Nampa the first fall frost follows around October 13.
- What is the rainy season in Nampa?
- Nampa sees its heaviest rain in December (around 1.4 inches), part of roughly 11 inches a year.
- What is the warmest month in Nampa?
- The warmest stretch in Nampa comes in July, around 75°F on average.
- What is the coldest month in Nampa?
- On average January is the chilliest month in Nampa, about 31°F.
- When can I start a vegetable garden in Nampa?
- Frost-hardy sowings begin at April 29 in Nampa; warm-season starts follow two weeks on.
- How many rainy days does Nampa get?
- Nampa records around 37 days of measurable precipitation annually.
- What hardiness zone is Nampa?
- Nampa sits in the USDA zone set by January lows near 31°F; the USDA ZIP tool gives the band.
- What is the 10-day forecast for Nampa?
- Nampa'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 Nampa?
- See this week's day-by-day rain chances for Nampa in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Nampa?
- Current conditions for Nampa and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Nampa forecast updated?
- The Nampa forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Nampa?
- Today's sunrise and sunset times for Nampa 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 Nampa?
- The next few days in Nampa's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Nampa sits at 43.6°N; its climate zone is warm-summer Mediterranean (Köppen approximation).
ZIP codes in Nampa
- 83651
- 83686
- 83687