Summit forecast for 3,340 ft · Sandwich Range · Updated 3x daily
As of August 16, 2026 at 8:20 PM ET
Middle Sister (3,340 ft) is currently 58°F (feels like 55°F) with overcast and SE winds at 7 mph, gusting to 15 mph. Today's freezing level is 13,222–15,092 ft. Expect the summit to run about 6°F colder than the trailhead. Trail conditions are rated Moderate.
Valley forecasts don't apply up high — temperatures drop about 3.4°F per 1,000 ft on Middle Sister.
| Elevation | Temp Range | Max Wind | Wind Chill (Low) |
|---|---|---|---|
| Summit 3,340 ft | 51° – 60°F | 24 mph | 51°F |
| Trailhead 2,000 ft | 54° – 66°F | 14 mph | 54°F |
Freezing level today: 13,222–15,092 ft
~3.4°F drop per 1,000ft
Tap a day header to expand to 3hr or hourly detail
Sunday Aug 16 | Today Aug 17 | Tomorrow Aug 18 | |||||||
|---|---|---|---|---|---|---|---|---|---|
| AM | PM | night | AM | PM | night | AM | PM | night | |
| Temperature & Wind | |||||||||
| Weather | sunny | cloudy | rain | rain | fog | fog | cloudy | drizzle | drizzle |
| Temp °F hi / lo | 53° 51° | 60° 55° | 59° 58° | 58° 58° | 62° 58° | 62° 60° | 61° 59° | 68° 60° | 65° 62° |
| Chill °F | — | — | — | — | — | — | — | — | — |
| Wind mph | 14 | 12 | 31 | 30 | 21 | 7 | 11 | 9 | 6 |
| Gust mph est. | 22 | 19 | 47 | 45 | 34 | 11 | 18 | 14 | — |
| Storm risk | — | — | — | — | — | — | — | mod | — |
| Precipitation | |||||||||
| Precip in (rain/snow) | - | - | 0.2 | 0.4 | - | - | - | 0.1 | - |
| Freezing ft | 14,394 ft | 14,627 ft | 14,618 ft | ||||||
| Conditions | |||||||||
| Cloud cover | 28% | 83% | 100% | 100% | 100% | 100% | 100% | 100% | 100% |
| Vis mi | 9 | clear | <0.1 | <0.1 | <0.1 | <0.1 | 1 | clear | clear |
| UV | 5 | 6 | — | 0 | 2 | — | 2 | 6 | — |
Tap a day header to expand AM/PM/Night detail
| Elevation | Sunday Aug 16 | Today Aug 17 | Tomorrow Aug 18 |
|---|---|---|---|
| lo/hi °F · wind mph & dir · chill °F | |||
| Summit 3,340 ft | 51/53° 14 | 58/58° 30 | 59/61° 11 |
| 3,300 ft | 51/53° 14 | 58/58° 30 | 59/61° 11 |
| 2,500 ft | 53/56° 8 | 59/60° 25 | 62/63° 9 |
| Trailhead 2,000 ft | 54/58° 6 | 61/61° 20 | 63/64° 7 |
4 more days of forecast — plan around the weather window, not just tomorrow.
Conditions synthesized from: NWS Higher Summits Forecast, NOAA Open-Meteo, Mount Washington Observatory, NETC Trip Reports, NOHRSC Snow Depth, Mt. Washington Avalanche Center, USGS Stream Levels, OpenWeather Air Quality.
AI-generated from public data. Always verify conditions before heading out — backcountry weather can change quickly.
As of August 16, 2026 at 8:20 PM ET: Middle Sister (3,340 ft) is currently 58°F (feels like 55°F) with overcast and SE winds at 7 mph, gusting to 15 mph. Today's freezing level is 13,222–15,092 ft. Expect the summit to run about 6°F colder than the trailhead. Trail conditions are rated Moderate.
Temperatures drop roughly 3.4°F per 1,000 ft of elevation on Middle Sister. Today the trailhead (2,000 ft) tops out around 66°F while the summit (3,340 ft) reaches about 60°F, with a wind chill as low as 51°F.
Winds at the summit of Middle Sister are forecast to reach 24 mph today. Above treeline there is no shelter from wind — plan layers around wind chill, not air temperature.
Today's freezing level (13,222–15,092 ft) is above the 3,340 ft summit of Middle Sister, so the full route should stay above freezing.