Hamilton, Montana Weather
Monsoon storms drench the south. Day 15 of summer. Read this microseason across nine climate regions →
Hamilton weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJul 4Overcast——87°48°—
- SundayJul 5Overcast——87°59°0°
- MondayJul 6Heavy Rain43%0.54″83°58°-4°
- TuesdayJul 7Overcast43%—89°56°+6°
- WednesdayJul 8Overcast10%—86°56°-3°
- ThursdayJul 9Clear——85°51°-1°
- FridayJul 10Clear——93°54°+8°
AQI 41 (Good), driven by Ozone. AQI up 16 in the last 6 hours — air quality is degrading. Ozone at AQI 45 — 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.
What's driving it
Ozone × UV × Sky
Ozone at AQI 45 — peak already passed at 1 PM under clear skies. Levels should ease through evening.
- Present
- AQI 45
- UV peak
- 1.6 at earlier today
- Sky at peak
- clear
- Projected peak
- AQI 45
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).








































If the first of July be rainy weather, 'twill rain more or less for four weeks together.
- Moonrise
- 12:00 AM
- Moonset
- 11:52 AM
- In sign
- ♓︎ Pisces
Monsoon storms drench the south
Hamilton at a glance
- Today vs. normal: 22°F above the seasonal normal for this latitude
- Last frost: May 24 (climatological average for this latitude)
- Microseason: Jul 1–5
- Planting window: Harvest early potatoes. Begin drying onions on the surface.
ZIP code: 59840
16-Day Forecast — Hamilton
- Sat87°48°1%
- Sun87°59°3%
- Mon83°58°43%
- Tue89°56°43%
- Wed86°56°10%
- Thu85°51°3%
- Fri93°54°2%
- Sat101°59°2%
- Sun98°62°4%
- Mon99°63°5%
- Tue105°63°12%
- Wed99°66°12%
- Thu97°60°10%
- Fri100°61°3%
- Sat100°65°9%
- Sun104°64°10%
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 — Hamilton
SPC includes Hamilton in the general thunderstorm area tomorrow — no severe risk, but storms are possible.
- TODAYNONENo severe risk
- TOMORROWTSTMGeneral Thunderstorms
- DAY 3TSTMGeneral Thunderstorms
Thunderstorms possible. Not severe, but capable of producing lightning and brief heavy rain.
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 Hamilton
- 59840