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

Big Sky, Montana Weather

Monsoon storms drench the south. Day 15 of summer. Read this microseason across nine climate regions →

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

Big Sky, MT
Saturday, July 4 at 6:33 PM
77
°
Clear
Feels like
68°
Humidity
18%
Wind
11 mph
Sunrise
11:43 PM
Sunset
3:16 PM
Big Sky, MT
Hour by hour · 24h
24-Hour ForecastBig Sky, MT: 24-hour forecast. Temperatures range from 55 to 79 degrees Fahrenheit.
L 55°H 79°
Big Sky, MT
7-day forecast
  1. Today
    Jul 4
    Overcast
    78°38°
  2. Sunday
    Jul 5
    Overcast
    23%
    79°55°+1°
  3. Monday
    Jul 6
    Showers
    64%
    0.24″
    75°53°-4°
  4. Tuesday
    Jul 7
    Heavy Showers
    64%
    0.62″
    68°50°-7°
  5. Wednesday
    Jul 8
    Light Showers
    31%
    0.13″
    77°51°+9°
  6. Thursday
    Jul 9
    Clear
    25%
    74°47°-3°
  7. Friday
    Jul 10
    Clear
    78°48°+4°
Big Sky, MT
Anemometer · 24h winds · from true
NESW
From · True
WSW
243° · backing 45°
Direction
WSW
243°
Sustained
11
mph
Gust
17
mph
Peak 24h
19
avg 6
Beaufort · 3 · GENTLE 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 6 · pk 19 @ 7:00p
0102030MPHB1B2B3B4B5B6-21h-18h-15h-12h-9h-6h-3h-24hNOWpk 2713SUSTGUST
−24h−18h−12h−6hnow
Light breeze backing 45° from the wsw.
Big Sky, MT
Barometer · 24h pressure · mb
STORMRAINCHANGEFAIRDRY9901000101010201030
Pressure · mb
796.3
-1.8 mb in 3h · falling · 23.51 inHg
Now
796.3
mb
3h
-1.8
mb
12h
+10.1
mb
24h
+1.0
mb
Regime · STORM
STORM
RAIN
CHANGE
FAIR
DRY
24h · Pressure · mb
range 787799
780785790795800805-21h-18h-15h-12h-9h-6h-3h-24hNOW799.4786.5796.6
−24h−18h−12h−6hnow
Deep low still deepening — rough seas, strong wind, persistent rain.
Big Sky, MT
Air quality
49
AQI
Good
+13 in 6h

AQI 49 (Good), driven by Ozone. AQI up 13 over the last 6 hours (gradual rise). Ozone at AQI 55 — peak already passed at 1 PM under clear skies. Levels should ease through evening.

OK No precautions needed for the general population; unusually sensitive individuals may consider limiting prolonged outdoor exertion.

PM 2.5Good
0.8μg/m³
PM 10Good
1μg/m³
NO₂Good
0μg/m³
OzoneDRIVERUnhealthy SG
110μg/m³
UV IndexModerate
2.3

What's driving it

Ozone × UV × Sky

Ozone at AQI 55 — peak already passed at 1 PM under clear skies. Levels should ease through evening.

Present
AQI 55
UV peak
1.8 at earlier today
Sky at peak
clear
Projected peak
AQI 55
Big Sky, MT
Sky cover · visibility · 24h
Cloud cover
1%
CLEAR
100%0%−24h−18h−12h−6hnow

Visibility
170.2mi
UNLIMITED
181 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
00:33 UTC · Big Sky, MT · 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
00:33 UTC · Big Sky, MT · NOAA NESDIS / STAR · 5-min cadence · up to 10000 px
Big Sky, MT
Satellite · infrared · animated
Big Sky, MT
Loading IR frames…
IR · cloud-top temp© RainViewer · Carto
Big Sky, MT
Almanac · Saturday, July 4
If the first of July be rainy weather, 'twill rain more or less for four weeks together.
Civil dawn
5:07 AM
Sunrise
11:43 PM
Daylight
15h 33m
Sunset
3:16 PM
Civil dusk
9:54 PM
Planting note
Harvest early potatoes. Begin drying onions on the surface.
Big Sky, MT
The moon
Waning Gibbous
77% illuminated
Moonrise
11:49 PM
Moonset
11:40 AM
In sign
♓︎ Pisces
Big Sky, MT
Microseason
Jul 1–5

Monsoon storms drench the south

insect
Jan 151% of the yearDec 31

Read this microseason across nine climate regions →

Big Sky at a glance

  • Today vs. normal: 11°F above the seasonal normal for this latitude
  • Last frost: May 18 (climatological average for this latitude)
  • Microseason: Jul 1–5
  • Planting window: Harvest early potatoes. Begin drying onions on the surface.

ZIP code: 59716

16-Day Forecast — Big Sky

  1. Sat78°38°1%
  2. Sun79°56°23%
  3. Mon75°53°64%
  4. Tue68°50°64%
  5. Wed77°51°31%
  6. Thu74°47°25%
  7. Fri78°48°2%
  8. Sat86°54°2%
  9. Sun91°60°4%
  10. Mon88°59°13%
  11. Tue92°60°32%
  12. Wed92°61°24%
  13. Thu90°61°24%
  14. Fri90°59°26%
  15. Sat93°59°15%
  16. Sun87°57°16%

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

Right now in the garden

Peak growing season

As of July 5, 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.

SPC Convective Outlook

Storm Prediction Center — Big Sky

SPC has placed Big Sky in the Marginal Risk category for severe thunderstorms tomorrow.

  • TODAYNONENo severe risk
  • TOMORROWMRGLMarginal Risk
  • DAY 3TSTMGeneral Thunderstorms

Isolated severe storms possible. Limited threat for hail or damaging wind.

Source: NOAA / NWS Storm Prediction Center categorical convective outlook. Outlooks are re-issued multiple times per day; this page reflects the most recent SPC polygons covering the city’s coordinates.

ZIP codes in Big Sky

  • 59730
  • 59716

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.