The Isolation-Monroe-Jefferson-Cog is a 14.4-mile point-to-point with 4,542 ft of elevation gain.
Submitted by shamuswilkie
14.4 mi • 4,542 ft gain • 7-12 hours • Mt Isolatoon
Feels like 29°F
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Today Aug 29 | Tomorrow Aug 30 | Monday Aug 31 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| AM | PM | night | AM | PM | night | AM | PM | night | |
| Temperature & Wind | |||||||||
| Weather | sunny | sunny | cloudy | cloudy | rain | drizzle | sunny | sunny | cloudy |
| Temp °F hi / lo | 46° 45° | 47° 45° | 50° 48° | 48° 47° | 50° 48° | 50° 47° | 46° 46° | 50° 48° | 51° 49° |
| Chill °F | 39° | 37° | 38° | 36° | 39° | 37° | 39° | 44° | 45° |
| Wind mph | 13 | 20 | 39 | 43 | 36 | 35 | 17 | 8 | 10 |
| Gust mph est. | 21 | 32 | 62 | 60 | 58 | 56 | 26 | — | — |
| Precipitation | |||||||||
| Precip in (rain/snow) | - | - | - | - | 0.4 | 0.1 | - | - | - |
| Freezing ft | 12,256 ft | 11,685 ft | 13,201 ft | ||||||
| Conditions | |||||||||
| Cloud cover | - | - | 100% | 100% | 100% | 100% | - | - | 100% |
| Vis mi | 10 | clear | clear | 9 | <0.1 | clear | clear | clear | clear |
| UV | 5 | 7 | — | 4 | 6 | — | 5 | 7 | — |
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| Elevation | Today Aug 29 | Tomorrow Aug 30 | Monday Aug 31 |
|---|---|---|---|
| lo/hi °F · wind mph & dir · chill °F | |||
| Summit 5,712 ft | 45/46° 13 | 47/48° 43 | 46/46° 17 |
| 5,000 ft | 46/47° 14 | 50/52° 42 | 49/50° 12 |
| 4,100 ft | 47/48° 13 | 53/55° 38 | 53/54° 9 |
| 3,300 ft | 48/51° 13 | 56/58° 31 | 55/59° 7 |
| 2,500 ft | 50/55° 9 | 59/61° 19 | 53/63° 6 |
| Trailhead 2,000 ft | 51/57° 8 | 61/63° 16 | 54/65° 5 |
4 more days of forecast — plan around the weather window, not just tomorrow.
Full hourly summit forecasts: Mount Jefferson weather · Mount Monroe weather · Mount Isolation weather
The Isolation-Monroe-Jefferson-Cog is a 14.4-mile point-to-point in New Hampshire's White Mountains, starting at Mt Isolatoon. It climbs about 4,542 ft — an average of 316 ft per mile — which works out to roughly 7-12 hours at AMC book time. It summits 3 named peaks, topping out on Mount Jefferson at 5,712 ft: Mount Jefferson (5,712 ft), Mount Monroe (5,372 ft), Mount Isolation (4,004 ft). HikerNerd rates it Very Difficult on effort alone — check the current conditions above before committing, since weather above treeline changes the day far more than the numbers do.
Distance
14.4 mi
Elevation Gain
4,542 ft
Duration
7-12 hours
Trailhead
Mt Isolatoon
The Isolation-Monroe-Jefferson-Cog is 14.4 miles point to point, starting at Mt Isolatoon. At AMC book time — half the distance in hours plus 30 minutes per 1,000 ft of climbing — that works out to roughly 7-12 hours. Most parties take longer than book time on rough or above-treeline terrain, in winter, or with a heavy pack.
The Isolation-Monroe-Jefferson-Cog climbs about 4,542 ft over 14.4 miles — an average of roughly 316 ft of gain per mile. That figure is cumulative ascent across the whole point-to-point, not the difference between the trailhead and the high point.
HikerNerd rates the Isolation-Monroe-Jefferson-Cog Very Difficult, scored with the Shenandoah difficulty formula — √(elevation gain × 2 × distance) — applied to its 14.4 miles and 4,542 ft of gain. The score measures physical effort only. Above-treeline exposure, water crossings, and winter conditions can make a moderate-rated route the hardest day of your year, so check current conditions before committing.
The Isolation-Monroe-Jefferson-Cog summits 3 named peaks: Mount Jefferson, Mount Monroe, Mount Isolation.
The Isolation-Monroe-Jefferson-Cog starts at Mt Isolatoon. Check the trail alerts on this page before you drive — trailhead access and parking in the White Mountains change with closures and construction.
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