Charlo, Montana Weather
Paintbrush crowns the ridges. Day 88 of spring. Read this microseason across nine climate regions →
Charlo weather forecast — hour by hour, 7-day outlook, NOAA radar
- TodayJun 15Overcast——82°52°—
- TuesdayJun 16Overcast——82°60°0°
- WednesdayJun 17Overcast——76°49°-6°
- ThursdayJun 18Overcast——78°48°+2°
- FridayJun 19Overcast——81°54°+3°
- SaturdayJun 20Overcast10%—80°56°-1°
- SundayJun 21Overcast10%—76°56°-4°
AQI 40 (Good), driven by Ozone. AQI down 7 over the last 6 hours (gradual decline). Ozone at AQI 32. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
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 32. Overcast through the UV peak window (cloud cover ~100%) — afternoon ozone should stay flat.
- Present
- AQI 32
- UV peak
- 3.3 at 1 PM
- Sky at peak
- overcast
- Projected peak
- AQI 7
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).








































A summer fog for fair, a winter fog for rain.
- Moonrise
- 5:37 AM
- Moonset
- 10:06 PM
- In sign
- ♊︎ Gemini
Paintbrush crowns the ridges
Charlo at a glance
- Today vs. normal: 13°F below the seasonal normal for this latitude
- Last frost: May 31 (climatological average for this latitude)
- Microseason: Jun 11–15
- Planting window: Stake and prune tomato suckers. Watch for squash vine borers.
15-Day Forecast — Charlo
- Mon82°52°4%
- Tue82°60°4%
- Wed76°49°3%
- Thu78°48°2%
- Fri81°54°0%
- Sat80°56°10%
- Sun76°56°10%
- Mon78°51°8%
- Tue82°55°6%
- Wed78°57°6%
- Thu64°50°13%
- Fri67°46°20%
- Sat75°47°20%
- Sun83°52°16%
- Mon85°60°10%
Forecast data from Open-Meteo (CC BY 4.0).
Right now in the garden
Warm-season window is open
As of June 15, the last spring frost has passed for most years. Transplant tomatoes, peppers, eggplants, basil, and cucurbits (cucumbers, squash, melons) now. Direct-sow beans and corn into warm soil.
Microseason · June 11–15
Paintbrush crowns the ridges
Alpine wildflower wave accelerates; paintbrush and columbine peak in high meadows as daylight reaches its maximum.
Day 166 of 365 · Wedge 33 of 72
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | — | — |
| May | lettuce, peas, spinach, radishes | lettuce, peas, radishes |
| June | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | tomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | — | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
Charlo peaks at about 69°F in July and bottoms near 30°F in December; June brings the heaviest rain (2.6 inches) and December the least (0.9 inches).
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 30° | 0.9″ | 3 |
| February | 31° | 1.1″ | 3 |
| March | 39° | 0.9″ | 3 |
| April | 47° | 1.8″ | 4 |
| May | 55° | 2.3″ | 7 |
| June | 61° | 2.6″ | 7 |
| July | 69° | 1.0″ | 3 |
| August | 68° | 1.2″ | 3 |
| September | 59° | 1.5″ | 3 |
| October | 47° | 1.3″ | 4 |
| November | 36° | 1.1″ | 3 |
| December | 30° | 0.9″ | 3 |
Regional context
By the nearest station's NOAA NCEI 1991-2020 normals, Charlo sees 30°F Januarys and 69°F Julys, a 39°F range, plus around 16.7 inches of precipitation across 46 days.
Summer convection drives Charlo's precipitation: June logs 2.6 inches on 6.8 rainy days, against December's 0.9 inches on 2.6 — warm-season storms carry Charlo's moisture. That puts Charlo in a summer-convective cohort with places like Kicking Horse, MT, Ronan, MT and St. Ignatius, MT.
Charlo's growing window opens around late-May, once Charlo's overnight lows stop freezing — sow kale, peas, spinach, and parsnips. In Charlo, warm-season transplants — tomatoes, peppers, basil — wait two weeks past Charlo's frost date. Charlo's window closes around early-October as overnight lows return below freezing. In Charlo, low spots run 4-7°F colder than nearby slopes, nudging Charlo's frost dates a week.
Similar climates: Kicking Horse, MT, Ronan, MT, St. Ignatius, MT, Old Agency, MT, Ravalli, MT.
Frequently asked
- When does it freeze in Charlo?
- Frost typically leaves Charlo by mid-May and returns to Charlo near mid-October.
- What is the rainy season in Charlo?
- Rainfall in Charlo peaks in June near 2.6 inches, out of about 17 inches annually.
- What is the warmest month in Charlo?
- The warmest stretch in Charlo comes in July, around 69°F on average.
- What is the coldest month in Charlo?
- On average December is the chilliest month in Charlo, about 30°F.
- When can I start a vegetable garden in Charlo?
- Frost-hardy sowings begin at mid-May in Charlo; warm-season starts follow two weeks on.
- How many rainy days does Charlo get?
- Charlo averages about 46 days with measurable rain or snow each year.
- What hardiness zone is Charlo?
- Charlo's hardiness zone tracks its winter low; with December near 30°F, check the USDA ZIP map for the exact zone.
- What is the 10-day forecast for Charlo?
- Charlo'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 Charlo?
- See this week's day-by-day rain chances for Charlo in the daily forecast above, and the next 24 hours in the hourly chart.
- What is the weather like right now in Charlo?
- Current conditions for Charlo and the next 24 hours — temperature, precipitation chance, and wind by the hour — are in the hourly forecast chart above.
- How often is the Charlo forecast updated?
- The Charlo forecast on this page is built from Open-Meteo weather-model data and refreshes regularly through the day.
- When are sunrise and sunset in Charlo?
- Day length in Charlo peaks around the June solstice — earliest sunrise and latest sunset — and is shortest near the December solstice.
- How accurate is the weather forecast for Charlo?
- The next few days in Charlo's forecast are the most reliable; accuracy declines beyond about a week as weather-model uncertainty grows.
Climate
Charlo's cold semi-arid climate in Montana pairs 30°F Januarys with 69°F Julys, 39°F apart across the seasons.
Charlo sees close to 17 inches of precipitation annually, falling across some 46 wet days.
The 39°F gap between Charlo's summer and winter, at 47.4°N, shapes Charlo's frost calendar.
ZIP codes in Charlo
- 59824