Borah Peak & Lost River Range
Lost River Range, BLM Challis Field Office, A. Hedrick, BLM. Image by BLMIdaho via Wikimedia Commons, Public domain.
Today’s Forecast:
☀
91°F
Current Temperature
Clear
⚠️
Air Quality Alert
Air Quality Alert issued July 27 at 10:23AM MDT by NWS Pocatello ID (Expires: July 28, 2026 4:00 pm)
Show Alert Details & Instructions
Description:
AQAPIH
* WHAT...Air Quality Advisory because of degraded air quality.
Air Quality Index is forecast to be Unhealthy for Sensitive
Groups.
* WHERE...BONNEVILLE, BUTTE, CLARK, CUSTER,
FREMONT, JEFFERSON, MADISON, AND TETON COUNTIES.
* WHEN...THROUGH WEDNESDAY JULY 29TH.
* IMPACTS...Members of sensitive groups may experience health
effects. The general public is less likely to be affected.
Instructions:
Air pollutants can cause breathing difficulties for children, the
elderly, as well as persons with respiratory problems. Those
individuals who are sensitive to increased particulate matter or
smoke are encouraged to avoid prolonged or strenuous outdoor
activity during this advisory. Open burning is prohibited by air
quality rule. It is also recommended that all other individuals
limit prolonged or strenuous activity outdoors.
THIS STATEMENT IS ISSUED BY THE IDAHO DEPARTMENT OF ENVIRONMENTAL
QUALITY, AIR QUALITY GROUP. FOR MORE INFORMATION, CONTACT DEQ's
Idaho Falls Regional Office at (208)528-2650.
⚠️
Air Quality Alert
Air Quality Alert issued July 27 at 9:00AM MDT by NWS Pocatello ID (Expires: July 28, 2026 2:00 pm)
Show Alert Details & Instructions
Description:
AQAPIH
* WHAT...Air Quality Advisory because of degraded air quality.
Air Quality Index is forecast to be Unhealthy.
* WHERE...CASSIA, LINCOLN, AND MINIDOKA COUNTIES.
* WHEN...THROUGH WEDNESDAY JULY 29TH.
* IMPACTS...Some members of the general public may experience
health effects; members of sensitive groups may experience more
serious health effects.
Instructions:
Air pollutants can cause breathing difficulties for children, the
elderly, as well as persons with respiratory problems. Those
individuals who are sensitive to increased particulate matter or
smoke are encouraged to avoid prolonged or strenuous outdoor
activity during this advisory. Open burning is prohibited by air
quality rule. It is also recommended that all other individuals
limit prolonged or strenuous activity outdoors.
THIS STATEMENT IS ISSUED BY THE IDAHO DEPARTMENT OF ENVIRONMENTAL
QUALITY, AIR QUALITY GROUP. FOR MORE INFORMATION, CONTACT DEQ's
Twin Falls Regional Office at (208)736-2190.
⚠️
Air Quality Alert
Air Quality Alert issued July 27 at 8:52AM MDT by NWS Pocatello ID (Expires: July 28, 2026 12:00 pm)
Show Alert Details & Instructions
Description:
AQAPIH
* WHAT...Air Quality Advisory because of degraded air quality.
Air Quality Index is forecast to be Unhealthy for Sensitive
Groups.
* WHERE...FOR POWER, BANNOCK, AND BINGHAM COUNTIES.
* WHEN...THROUGH WEDNESDAY JULY 29TH.
* IMPACTS...Members of sensitive groups may experience health
effects. The general public is less likely to be affected.
Instructions:
Air pollutants can cause breathing difficulties for children, the
elderly, as well as persons with respiratory problems. Those
individuals who are sensitive to increased particulate matter or
smoke are encouraged to avoid prolonged or strenuous outdoor
activity during this advisory. Open burning is prohibited by air
quality rule. It is also recommended that all other individuals
limit prolonged or strenuous activity outdoors.
THIS STATEMENT IS ISSUED BY THE IDAHO DEPARTMENT OF ENVIRONMENTAL
QUALITY, AIR QUALITY GROUP. FOR MORE INFORMATION, CONTACT DEQ's
Pocatello Regional Office at (208)236-6160.
⚠️
Air Quality Alert
Air Quality Alert issued July 27 at 8:42AM MDT by NWS Pocatello ID (Expires: July 28, 2026 4:00 pm)
Show Alert Details & Instructions
Description:
AQAPIH
* WHAT...Air Quality Advisory because of degraded air quality.
Air Quality Index is forecast to be Unhealthy for Sensitive
Groups.
* WHERE...BONNEVILLE, BUTTE, CLARK, CUSTER, FREMONT, JEFFERSON,
MADISON, AND TETON COUNTIES.
* WHEN...THROUGH WEDNESDAY JULY 29TH.
* IMPACTS...Members of sensitive groups may experience health
effects. The general public is less likely to be affected.
Instructions:
Air pollutants can cause breathing difficulties for children, the
elderly, as well as persons with respiratory problems. Those
individuals who are sensitive to increased particulate matter or
smoke are encouraged to avoid prolonged or strenuous outdoor
activity during this advisory. Open burning is prohibited by air
quality rule. It is also recommended that all other individuals
limit prolonged or strenuous activity outdoors.
THIS STATEMENT IS ISSUED BY THE IDAHO DEPARTMENT OF ENVIRONMENTAL
QUALITY, AIR QUALITY GROUP. FOR MORE INFORMATION, CONTACT DEQ's
Idaho Falls Regional Office at (208)528-2650.
⚠️
Red Flag Warning
Red Flag Warning issued July 27 at 12:34AM MDT until July 27 at 9:00PM MDT by NWS Pocatello ID (Expires: July 27, 2026 10:00 pm)
Show Alert Details & Instructions
Description:
...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 9 PM MDT
THIS EVENING FOR GUSTY WINDS AND LOW RELATIVE HUMIDITY FOR FIRE
WEATHER ZONES 475 AND 476...
* AFFECTED AREA...Fire Weather Zone 475 East Salmon River
Mountains/Salmon NF and Fire Weather Zone 476 Lemhi and Lost
River Range/Challis NF.
* WINDS...Southwest 10 to 20 mph with gusts up to 30 mph. Locally
high gusts are possible due to virga.
* RELATIVE HUMIDITY...As low as 13 percent.
* IMPACTS...Wind and low humidity can lead to rapid spread of
fire and more intense fire in receptive fuels.
Instructions:
A Red Flag Warning means that critical fire weather conditions
are either occurring now, or will shortly based on these criteria
for Southeastern Idaho:
- Relative humidity at or below 15 percent and wind gusts of at
least 25 mph in the mountains, or 30 mph in the Snake Plain.
This Afternoon:Sunny, with a high near 61. Southwest wind around 18 mph, with gusts as high as 26 mph.
Tonight:Areas of smoke. Mostly clear, with a low around 46. Southwest wind 8 to 17 mph, with gusts as high as 23 mph.
Tuesday:Areas of smoke. Sunny, with a high near 62. Southwest wind 7 to 22 mph, with gusts as high as 32 mph.
Today’s Report:
Hiking
Use Caution
49
/100
Use Caution for hiking. High near 60°F. Low rain risk (6%). Light wind (18 mph). Smoke or haze in forecast.
- Temp: Favorable conditions
- Rain: Favorable conditions
- Wind: Favorable conditions
- Smoke: Marginal weather factor
- Thunderstorm: Favorable conditions
Tomorrow's Outlook:
Use Caution
48/100
Use Caution for hiking. High near 62°F. Breezy winds (22 mph). Smoke or haze in forecast.
Camping
Use Caution
48
/100
Use Caution for camping. High near 60°F. Low rain risk (6%). Breezy winds (18 mph). Smoke or haze in forecast.
- Temp: Favorable conditions
- Rain: Favorable conditions
- Wind: Marginal weather factor
- Smoke: Marginal weather factor
- Thunderstorm: Favorable conditions
Tomorrow's Outlook:
Use Caution
46/100
Use Caution for camping. High near 62°F. Breezy winds (22 mph). Smoke or haze in forecast.
Outdoor Events / Activities
Use Caution
47
/100
Use Caution for outdoor events / activities. High near 60°F. Low rain risk (6%). Breezy winds (18 mph). Smoke or haze in forecast.
- Temp: Marginal weather factor
- Rain: Favorable conditions
- Wind: Marginal weather factor
- Smoke: Marginal weather factor
- Thunderstorm: Favorable conditions
Tomorrow's Outlook:
Use Caution
46/100
Use Caution for outdoor events / activities. High near 62°F. Breezy winds (22 mph). Smoke or haze in forecast.
About Borah Peak & Lost River Range
Borah Peak & Lost River Range is an Idaho destination for Idaho’s highest summit and an exposed high-alpine hiking destination.
Make the Most of a Borah Peak & Lost River Range Day
Match the route, launch, facility, or turnaround time to wind, precipitation, temperature, smoke, water, snow, road access, and daylight. Keep a shorter or more sheltered backup ready.
Weather Tips for the Lost River Range
- Check official access notices, alerts, road or trail conditions, fire restrictions, and local forecasts before leaving.
- Turn around before exposed ridges, canyon rims, dunes, or open ground become unsafe in lightning, heat, smoke, wind, or poor visibility.
- Carry layers, water, navigation, sun protection, and seasonal traction or flotation appropriate to the activity.
- Allow extra time for remote roads, mountain passes, wildfire smoke, spring runoff, and limited winter daylight.
Nearby Towns and Areas
This page can also be useful when planning outdoor time near:
- Mackay
- Trail Creek Road
- Mount Idaho
- Leatherman Peak
- Challis
Plan Around the Conditions
Choose the safest version of a Borah Peak & Lost River Range day by matching the activity to current wind, precipitation, temperature, smoke, water or snow conditions, access, and daylight.
7-Day Forecast for Borah Peak, ID
Borah Peak & Lost River Range Weather by Season
Winter
Winter at Borah Peak & Lost River Range can bring snow, ice, wind, short daylight, and rapidly changing road or trail access.
Spring
Spring brings freeze-thaw mud, snowmelt, high rivers, cold water, and lingering mountain snow. Lower routes usually open well before high passes and backcountry trailheads.
Summer
Summer usually offers the broadest access, but dry heat, thunderstorms, lightning, wildfire smoke, fire restrictions, reservoir wind, and cold mountain water can alter plans.
Fall
Fall brings cooler air, shorter daylight, hunting-season awareness, and early snow at elevation. Confirm seasonal services and allow extra travel time on remote roads.
Key Climate Data Points
- Annual average temperature: around 35–43°F in nearby valleys, using the relevant local and elevation context.
- Annual snowfall: often 80–150+ inches in high terrain.
- Warmest months: July and August are normally warmest.
- Coolest months: December and January are typically coolest.
- Wettest season: winter and spring usually provide the greatest mountain precipitation, with local variation.
- Driest season: midsummer is generally driest, despite isolated thunderstorms.
- Best outdoor window: June through October for warm-season access, with midwinter best at established winter destinations.