4,004 ft · Presidential Range · month-by-month from 271 observed days
June through September is the reliable window: 85% of observed days rated Good or Moderate. January was the toughest month, with 97% of days at Difficult or worse.
| Month | Days observed | Good/Moderate | Recurring hazards |
|---|---|---|---|
| January | 31 | 3% | severe wind chill, dangerous wind, snow, ice |
| February | 28 | 4% | severe wind chill, snow, dangerous wind, ice |
| March | 29 | 7% | ice, severe wind chill, snow, dangerous wind |
| April | 30 | 27% | ice, mud, postholing, dangerous wind |
| May | 31 | 32% | mud, ice, monorail, severe wind chill |
| June | 30 | 77% | mud, slick ledges, dangerous wind, severe wind chill |
| July | 31 | 81% | mud, dangerous wind, slick ledges, severe wind chill |
| August | 31 | 87% | mud, slick ledges, severe wind chill, dangerous wind |
Right now on Mount Isolation
Moderateupdated Sep 21, 4 AMJune through September is the reliable window: 85% of observed days rated Good or Moderate. January was the toughest month, with 97% of days at Difficult or worse.
Yes, with winter gear and experience: in our observations, 95% of December-March days rated Difficult or Dangerous. Full winter traction, insulation, and a hard turnaround plan are the baseline; check live conditions the morning you go.
95% of observed September days rated Good or Moderate; recurring hazards were mud, slick ledges, severe wind chill. Today's actual report is on the live conditions page.
Methodology: severity shares are observed, not forecast. Each day's rating is the consensus of our AI-synthesized condition reports for Mount Isolation that day, collected since December 2025 (271 days so far). Months keep filling in as the archive grows. Pair the history with the live report and a summit forecast before you commit to a drive.
Bar shows the share of observed days at each severity; the number is the share rated Good or Moderate. Good · Moderate · Difficult · Dangerous
| September |
| 21 |
| 95% |
| mud, slick ledges, severe wind chill, dangerous wind |
| December | 9 | 0% | severe wind chill, dangerous wind, snow, ice |