Lewis and Clark County, Montana, United States

Last updated: 1:50 PM CDT  ·  Refresh
11°C
Feels like 8°
Partly Cloudy
▲ 14°  /  ▼ 2°
Wind
4 mph SW
Humidity
66%
Dew Point
6°
Pressure
24.02 inHg
Visibility
8 mi
UV Index
6.9
Cloud Cover
54%
Sunrise
7:03 AM
Sunset
7:45 PM
Drag to pan · double-click to forecast a point
WeatherAI™ Analysis

WeatherAI Analysis: Lewis and Clark County is currently partly cloudy at 11°C. Dry conditions are expected through the next 24 hours. Sunrise: 7:03AM · Sunset: 7:45PM.

Alerts

No active alerts for this location.
33 AQI · Good Dominant: O3 Air Quality
Hourly Forecast · Next 24 Hours
Now
11°
31%
1 PM
13°
30%
2 PM
13°
34%
3 PM
13°
34%
4 PM
13°
37%
5 PM
13°
20%
6 PM
12°
22%
7 PM
10°
27%
8 PM
9°
27%
9 PM
8°
24%
10 PM
7°
34%
11 PM
7°
12%
12 AM
6°
12%
1 AM
4°
18%
2 AM
3°
18%
3 AM
3°
24%
4 AM
3°
37%
5 AM
2°
37%
6 AM
2°
41%
7 AM
2°
40%
8 AM
3°
40%
9 AM
4°
30%
10 AM
4°
30%
11 AM
5°
30%
7-Day Forecast
Today
14° 2°
Partly Cloudy with a 34% chance of rain.
Mon
12° 2°
Partly Cloudy with a 41% chance of rain.
Tue
15° 3°
Partly Cloudy.
Wed
18° 4°
Clear with a 38% chance of rain.
Thu
26° 7°
Clear with a 25% chance of rain.
Fri
22° 8°
Drizzle, 60% chance.
Sat
22° 9°
Drizzle, 60% chance.
TimeTempConditionsPrecipWindHumidity
Now 11° Partly Cloudy 31% 4 mph SW 66%
1 PM 13° Partly Cloudy 30% 10 mph WSW 64%
2 PM 13° Mostly Clear 34% 12 mph W 60%
3 PM 13° Rain 34% 13 mph W 55%
4 PM 13° Mostly Clear 37% 12 mph W 53%
5 PM 13° Mostly Clear 20% 11 mph W 53%
6 PM 12° Partly Cloudy 22% 9 mph W 55%
7 PM 10° Mostly Cloudy 27% 8 mph WNW 61%
8 PM 9° Overcast 27% 8 mph W 66%
9 PM 8° Overcast 24% 8 mph W 68%
10 PM 7° Overcast 34% 9 mph W 69%
11 PM 7° Mostly Cloudy 12% 9 mph WSW 70%
12 AM 6° Mostly Cloudy 12% 10 mph WSW 73%
1 AM 4° Mostly Cloudy 18% 8 mph W 75%
2 AM 3° Mostly Cloudy 18% 8 mph W 78%
3 AM 3° Partly Cloudy 24% 12 mph W 80%
4 AM 3° Mostly Cloudy 37% 14 mph WSW 83%
5 AM 2° Mostly Cloudy 37% 16 mph WSW 84%
6 AM 2° Rain 41% 16 mph W 85%
7 AM 2° Rain 40% 18 mph W 85%
8 AM 3° Rain 40% 19 mph W 85%
9 AM 4° Rain 30% 18 mph W 83%
10 AM 4° Rain 30% 18 mph W 82%
11 AM 5° Rain 30% 18 mph W 80%
15-Day Forecast
Today
9/13
Partly Cloudy
34%
2°
14°
Mon
9/14
Partly Cloudy
41%
2°
12°
Tue
9/15
Partly Cloudy
16%
3°
15°
Wed
9/16
Clear
38%
4°
18°
Thu
9/17
Clear
25%
7°
26°
Fri
9/18
Drizzle
60%
8°
22°
Sat
9/19
Drizzle
60%
9°
22°
Sun
9/20
Clear
3%
9°
23°
Mon
9/21
Clear
25%
9°
22°
Tue
9/22
Drizzle
42%
9°
21°
Wed
9/23
Drizzle
60%
8°
23°
Thu
9/24
Drizzle
60%
8°
21°
Fri
9/25
Clear
60%
6°
18°
Sat
9/26
Drizzle
60%
6°
18°
Sun
9/27
Drizzle
60%
5°
18°
33
Good
U.S. Air Quality Index · Dominant: O3
50 100 150 200

Air quality is satisfactory and poses little or no health risk.

Pollutant Breakdown · Today
PM2.5
Fine particulate matter
16 AQI 2.8 µg/m³
O3
Ground-level ozone
Dominant
33 AQI 36 ppb
3-Day Outlook
DayAQICategoryO₃PM2.5
Mon 33 Good 33 16
Tue 32 Good 32 11
Wed 28 Good 28 11
About the Air Quality Index
0–50 Good
51–100 Moderate
101–150 Unhealthy for Sensitive Groups
151–200 Unhealthy
201–300 Very Unhealthy
301–500 Hazardous

The U.S. AQI runs 0–500. The overall value equals the highest individual pollutant sub-index, and the dominant pollutant is the one driving it. PM2.5 (fine particles) is reported in µg/m³ and ozone (O3) in ppb. Forecast source: NWS NAQFC.

1000850700500400300250200150100 -40-30-20-10010203040 0.41247101624 LCLLFCEL0°C Temperature (°C) Pressure (hPa)
Temp Dewpoint Parcel (SB) CAPE CIN Dry adiabat Moist adiabat Mixing ratio
RAP
Valid Sun Sep 13, 17:00'Z' · F0 · 130 (13 km CONUS/NA)
Hodograph · kt
10 20 30 40 50 60 70 SM
0–1 1–3 3–6 6–9 km
Instability
SBCAPE5 J/kg
MLCAPE18 J/kg
MUCAPE5 J/kg
SBCIN0 J/kg
MLCIN0 J/kg
Lifted Index0.0
Kinematics
0–6 km Shear55 kt
0–1 km Shear18 kt
Eff. Shear—
0–1 km SRH44
0–3 km SRH152
Eff. SRH—
Storm Motion227° @ 37 kt
0–1 km EHI0.0
Composite Parameters
Sig. Tornado0.0
STP (eff)—
Supercell—
K-Index—
Thermo & Levels
PWAT0.58 in
0–3 km LR6.2 °C/km
700–500 LR6.7 °C/km
Total Totals—
LCL758 hPa
LFC813 hPa
EL499 hPa
Freezing Lvl6,001 ft