Weather StoryAlmanac, microseasons, and the day's weather story.

Boise, Idaho Weather

Summer heat breaks with monsoon. Day 43 of summer. Read this microseason across nine climate regions →

Boise weather forecast — hour by hour, 7-day outlook, NOAA radar

Boise, ID
Sunday, August 2 at 8:59 AM
65
°
Clear
Feels like
59°
Humidity
37%
Wind
7 mph
Sunrise
12:35 AM
Sunset
3:06 PM
Boise, ID
Hour by hour · 24h
24-Hour ForecastBoise, ID: 24-hour forecast. Temperatures range from 53 to 86 degrees Fahrenheit.
L 53°H 86°
Boise, ID
7-day forecast
  1. Today
    Aug 2
    Partly Cloudy
    —
    —
    86°62°—
  2. Monday
    Aug 3
    Clear
    —
    —
    82°53°-4°
  3. Tuesday
    Aug 4
    Overcast
    —
    —
    91°56°+9°
  4. Wednesday
    Aug 5
    Overcast
    —
    —
    97°68°+6°
  5. Thursday
    Aug 6
    Clear
    —
    —
    104°74°+7°
  6. Friday
    Aug 7
    Clear
    —
    —
    106°79°+2°
  7. Saturday
    Aug 8
    Clear
    —
    —
    100°75°-6°
Boise, ID
Next 24 hours · Cool now
HOT 90°45°70°95°12p6p12a6anow 63°high 86°low 53°
Boise, ID
Anemometer · 24h winds · from true
NESW
From · True
NW
314° · veering 173°
Direction
NW
314°
Sustained
7
mph
Gust
11
mph
Peak 24h
26
avg 8 mph
Beaufort · 2 · LIGHT BRZ
0
CALM
<1
1
LIGHT AIR
1–3
2
LIGHT BRZ
4–7
3
GENTLE BRZ
8–12
4
MOD BRZ
13–18
5
FRESH BRZ
19–24
6
STRONG BRZ
25–31
7
NEAR GALE
32–38
24h · sust vs gust · mph
avg 8 mph · pk 26 mph @ 1:00a
01020MPHB1B2B3B4B5-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 174SUSTGUST
−24h−18h−12h−6hnow
Light breeze veering 173° from the nw.
Boise, ID
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
918.4
+1.1 mb in 3h · rising · 27.12 inHg
Now
918.4
mb
3h
+1.1
mb
12h
+1.5
mb
24h
-0.1
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 916–921
910915920925-21h-18h-15h-12h-9h-6h-3h-24hNOW921.0916.2918.3
The low is filling — pressure climbing out of storm territory.
Boise, ID
Air quality
139
AQI
Unhealthy for Sensitive Groups
↓-17 in 6h▲Peak ~148 @ 5 PM

AQI 139 (Unhealthy for Sensitive Groups), driven by PM2.5. AQI down 17 over the last 6 hours — air quality is improving sharply. PM2.5 at 49.6 µg/m³, PM10 at 51.9 µg/m³ — typical background levels with no transport signature.

CAUTION Sensitive groups (children, elderly, respiratory conditions) should limit prolonged outdoor exertion, especially during the projected peak around 5 PM.

PM 2.5DRIVERUnhealthy SG
49.6μg/m³
PM 10Good
52μg/m³
NO₂Good
6μg/m³
OzoneModerate
92μg/m³
UV IndexLow
0.5

What's driving it

Ozone × UV × Sky

Ozone at AQI 43 now. With UV 1.7 peaking around 1 PM under clear skies, surface ozone likely climbs to AQI 10.

Present
AQI 43
UV peak
1.7 at 1 PM
Sky at peak
clear
Projected peak
AQI 10

PM × Wind × Precip

PM2.5 at 49.6 µg/m³, PM10 at 51.9 µg/m³ — typical background levels with no transport signature.

PM2.5/PM10
0.96
Wind
light
Recent rain
0h in last 6h
Pattern
background

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).

7-DAY AQI TREND50100SUNMONTUEWEDTHUFRISATSUN7-DAY PM2.5 TREND · μg/m³890
Boise, ID
Sky cover · visibility · 24h
Cloud cover
0%
CLEAR
100%0%−24h−18h−12h−6hnow
Visibility
54.2mi
UNLIMITED
185 mi0 mi−24h−18h−12h−6hnow
Earth · GOES-19 ABI
Full Disk · Visible · GeoColor
GOES-19 full disk Visible · GeoColor
True-color daytime, blue/IR sandwich at night
14:59 UTC · Boise, ID · NOAA NESDIS / STAR · up to 10848 px
Continental US · GOES-19 ABI
CONUS Sector · Visible · GeoColor
GOES-19 CONUS Visible · GeoColor
Daytime true-color, blue-light/IR sandwich at night
14:59 UTC · Boise, ID · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Boise, ID
Satellite · infrared · animated
Boise, ID
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Boise, ID
Almanac · Sunday, August 2
Red sky at night, sailor's delight.
Civil dawn
6:03 AM
Sunrise
12:35 AM
Daylight
14h 31m
Sunset
3:06 PM
Civil dusk
9:40 PM
Planting note
Sow fall peas. Start kale and collard seedlings for fall.
Boise, ID
The moon
Waning Gibbous
84% illuminated
Moonrise
10:31 PM
Moonset
10:56 AM
In sign
♓︎ Pisces
Boise, ID
Microseason
Aug 1–5

Summer heat breaks with monsoon

plant
Jan 159% of the yearDec 31

Read this microseason across nine climate regions →

Boise at a glance

  • Today vs. normal: 6°F above the seasonal normal for this latitude
  • Last frost: May 8 (climatological average for this latitude)
  • Microseason: Aug 1–5
  • Planting window: Sow fall peas. Start kale and collard seedlings for fall.

ZIP codes: 83702, 83703, 83704, 83705, 83706, 83709, 83712, 83713 +3 more

16-Day Forecast — Boise

  1. Sun86°62°0%
  2. Mon82°53°0%
  3. Tue91°56°0%
  4. Wed97°68°0%
  5. Thu104°74°0%
  6. Fri106°79°0%
  7. Sat100°75°0%
  8. Sun99°74°1%
  9. Mon97°74°2%
  10. Tue100°71°2%
  11. Wed99°75°1%
  12. Thu92°71°3%
  13. Fri92°67°6%
  14. Sat99°74°6%
  15. Sun99°75°13%
  16. Mon96°71°15%

Forecast data from Open-Meteo (CC BY 4.0).

Live wind & temperature near Boise

Right now in the garden

Peak growing season

As of August 2, the growing season is at its peak — frost is months away. Continue succession-planting beans and summer squash. Start fall brassicas (broccoli, cabbage, kale) from seed indoors for transplanting in late summer.

Sun & seasons in Boise

Boise 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.

Nampa, the state’s largest city, lies about 17 miles to the W. The nearest town Boise tracks is Meridian, roughly 8 miles to the W.

Air quality in Boise’s county has trended cleaner since 2020; its cleanest year on record was 2025 (median AQI 42). See the full air-quality history for Boise.

January 1–5: Deep freeze grips the high peaks.January 6–10: Ice thickens on alpine tarns.January 11–15: Springs stir beneath locked earth.January 16–20: Grouse call from the transition zone.January 21–25: First signals of the soil's turning.January 26–31: Stream water crystallizes thick.February 1–5: The year's coldest fortnight begins.February 6–10: East wind carries a subtle promise.February 11–15: Snowmelt springs whisper beneath ice.February 16–20: Red-wing calls rise from the wetlands.February 21–25: Rain begins to trace the snowline upward.February 26–28: Mist gathers in the warming canyons.March 1–5: Grass and trees stir from their sleep.March 6–10: Hibernators break through frozen ground.March 11–15: First blooms open to the spring sun.March 16–20: Mountain bluebirds return to the summits.March 21–25: Spring equinox at the divide.March 26–31: Aspen catkins burst in clusters.April 1–5: Thunderstorms rumble over granite peaks.April 6–10: Swallows and swifts slice the warming sky.April 11–15: Sandhill cranes call through the wetlands.April 16–20: Rainbows arch over the snowfields.April 21–25: New growth explodes across the montane.April 26–30: Last frost yields to summer growth.May 1–5: Wildflowers crest the high meadows.May 6–10: Summer monsoon clouds gather southward.May 11–15: Snowmelt crests toward the divide.May 16–20: High country wildflowers peak.May 21–25: Summer heat accelerates the growing season.May 26–31: Summer settles into the high country.June 1–5: Pikas hayfeeding in granite peaks.June 6–10: Glacier lily carpets the snowmelt.June 11–15: Paintbrush crowns the ridges.June 16–20: Thunderheads build by noon.June 21–25: Long light holds the peaks.June 26–30: Monsoon moisture drifts north.July 1–5: Monsoon storms drench the south.July 6–10: Wind builds through canyons.July 11–15: Lightning crowns every peak.July 16–20: Elk herds claim alpine meadows.July 21–25: Pika caches reach their peak.July 26–31: Monsoon pulses weaken northward.August 1–5: Summer heat breaks with monsoon.August 6–10: First frost creeps to peaks.August 11–15: Cool wind returns from north.August 16–20: Monsoon clouds gather over the peaks.August 21–25: The monsoon breaks into scattered showers.August 26–31: Summer insects thin as autumn wind rises.September 1–5: Elk descend from summer high meadows.September 6–10: Dew crystallizes on high grass at dawn.September 11–15: Hawks begin the long crossing southward.September 16–20: Equinox: darkness claims the high passes.September 21–25: Thunder retreats as the monsoon dies.September 26–30: First frost hardens the high valleys.October 1–5: October: the aspen stands reach their peak.October 6–10: Aspen gold slides downslope with the chill.October 11–15: Snow settles on the high passes.October 16–20: Elk bugling fades as rut nears its end.October 21–25: First hard frost grips the basin.October 26–31: Late rains settle into November patterns.November 1–5: Aspen canopy falls to earth.November 6–10: Granite bones emerge from cover.November 11–15: Earth begins to harden.November 16–20: Bare ranges hold silence.November 21–25: Snow returns to the peaks.November 26–30: North wind strips the landscape.December 1–5: Deep darkness settles over the ranges.December 6–10: Winter locks the high country.December 11–15: Elk withdraw to winter range.December 16–20: Ice thickens across frozen water.December 21–25: Winter solstice — the sun returns.December 26–31: The year closes in silence.🌱February 14 — First skunk-cabbage spathes thaw their way up☀️March 20 — Spring equinox — day and night balance🌸April 5 — Cherry blossoms peak in the parks🐦May 10 — Warbler migration peaks along the coast✨May 25 — First fireflies scout the meadows at dusk🌞June 21 — Summer solstice — longest day🦗July 25 — Peak cicada chorus in the afternoons🌊August 18 — Warmest sea-surface temperatures of the year🍂September 22 — Autumn equinox — the slow turn❄️October 25 — First widespread frost in the suburbs🍁November 10 — Peak leaf color across the Hudson Valley🌙December 21 — Winter solstice — longest night

Microseason · August 1–5

Summer heat breaks with monsoon

Late summer monsoon surge; southern reaches drench under Gulf moisture; northern peaks cool rapidly as monsoon remnants push north.

Day 214 of 365 · Wedge 43 of 72

The solar year drawn as a wheel of 72 five-day windows. Each wedge is one microseason; the four colored arcs mark winter, spring, summer, and autumn; the small icons sit at notable phenological events. The crimson pointer creeps clockwise as the year turns.

Planting calendar

MonthPlantHarvest
January——
February——
March——
April——
Maylettuce, peas, spinach, radisheslettuce, peas, radishes
Junelettuce, peas, spinach, radishes, tomatoes, peppers, beans, squashlettuce, peas, radishes
Julytomatoes, peppers, beans, squashtomatoes, beans, summer squash
Augusttomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
Septemberfall brassicas, garlic (overwinter), carrotstomatoes, beans, summer squash
October—winter squash, tomatoes (last)
November——
December——

A year in weather

Boise's warmest month is July (~77°F mean) and its coldest is December (~32°F). Rainfall peaks in December (1.5 inches) and bottoms out in August (0.2 inches).

MonthMean tempPrecipRainy days
January32°1.4″5
February38°1.0″4
March45°1.3″5
April51°1.2″4
May60°1.4″4
June68°0.8″2
July77°0.2″1
August76°0.2″0
September66°0.4″1
October53°0.8″2
November40°1.2″4
December32°1.5″5

Regional context

Per NOAA NCEI 1991-2020 normals, Boise runs from a 32°F January mean to 77°F in July, a 45°F seasonal spread, with near 11.5 inches of precipitation across about 38 wet days.

Boise's moisture rides winter storm tracks: December brings 1.5 inches over 4.8 wet days, while August sees only 0.2 inches across 0.4 days in the dry warm season. It is a winter-storm rhythm Boise shares with places like Garden City, ID, Hidden Springs, ID and Meridian, ID.

Once Boise passes late-May, overnight freezes fade and peas, lettuce, spinach, and radishes can be sown. Tomatoes and peppers do best set out two weeks later in Boise, once nights clear the mid-40s°F. By early-October, frost is back in Boise — protect or harvest anything tender. A creek-bottom lot in Boise can lag Boise's last frost 7-10 days behind a south slope.

Similar climates: Garden City, ID, Hidden Springs, ID, Meridian, ID, Kuna, ID, Eagle, ID.

Naturalist notes

Mountain bluebirds return to the Boise area in late March, their azure wings catching the strengthening spring light.

Chokecherry trees bloom throughout the foothills in late April, their white flower clusters marking the transition from cool to warm season.

Frequently asked

When does it freeze in Boise?
In Boise, expect the last spring frost near mid-May; Boise's first autumn frost comes around mid-October.
What is the rainy season in Boise?
December is the wettest month in Boise, about 1.5 inches on average; the year totals roughly 12 inches.
What is the warmest month in Boise?
Boise peaks in July, when the mean runs near 77°F.
What is the coldest month in Boise?
December is Boise's coldest month, averaging about 32°F.
When can I start a vegetable garden in Boise?
Around mid-May, start frost-hardy crops in Boise; tomatoes and basil belong a fortnight later.
How many rainy days does Boise get?
Expect roughly 38 wet days a year in Boise.
What hardiness zone is Boise?
With December around 32°F, Boise's zone reflects that minimum — the USDA ZIP map confirms Boise's band.
What is the 10-day forecast for Boise?
Boise'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 Boise?
See this week's day-by-day rain chances for Boise in the daily forecast above, and the next 24 hours in the hourly chart.
What is the weather like right now in Boise?
Current conditions for Boise and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
How often is the Boise forecast updated?
The Boise forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
When are sunrise and sunset in Boise?
Today's sunrise and sunset times for Boise 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 Boise?
The next few days in Boise's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.

Climate

Set in a warm-summer Mediterranean zone, Boise, Idaho swings from 32°F in the heart of winter to 77°F at midsummer — a 45°F arc.

Yearly precipitation in Boise totals around 12 inches, spread over about 38 days of rain or snow.

Boise's 45°F range, set by its 43.6°N position, drives frost timing and what thrives in Boise.

All cities in Idaho →

ZIP codes in Boise

  • 83703
  • 83702
  • 83706
  • 83705
  • 83704
  • 83709
  • 83712
  • 83716
  • 83713
  • 83725
  • 83720
  • 83701
  • 83708
  • 83715
  • 83717
  • 83722
  • 83724
  • 83728
  • 83729
  • 83735
  • 83756
  • 83799

Climate normals from the Open-Meteo Climate API. Köppen approximation from NOAA NCEI U.S. Climate Regions. See methodology for data sources, editorial rules, and corrections. Maintainer: Brian Tighe.