New Hampshire mountains

Mount Lafayette mountain forecast

5,249 ft (1,600 m) · prominence 3,320 ft (1,012 m) · New Hampshire

At the summit’s height the GFS model has 48°F and wind from the ENE at 27 mph, a wind chill of 39°F, Sat, Sep 26, 2:00 AM EDT. The freezing level is at 13,169 ft, above the summit. The National Weather Service forecast for saturday: mostly cloudy then chance light rain, high 56°F at its grid elevation of 3,579 ft.

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Mount Lafayette and the summits and ski areas around it. Each has its own page.

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Now

Summit
5,249 ft (1,600 m)
Forecast grid ground
3,579 ft (1,091 m)
Summit temperature
48°F
Summit wind
ENE 27 mph
Freezing level
13,169 ft
High at the summit, by lapse rate
50°F

The last tile carries the Weather Service’s high from its grid’s 3,579 ft up 1,670 ft to the summit at the standard atmosphere’s 6.5 °C per kilometer (about 3.6 °F per 1,000 ft). Real lapse rates vary: an inversion can make the summit warmer than the valley.

At the summit’s height

Temperature, wind and wind chill up there, and the freezing level, every six hours for three days.

TimeTempWindWind chillFreezing level
Sat, Sep 26, 2:00 AM EDT48°FENE 27 mph39°F13,169 ft7,920 ft above the summit
Sat, Sep 26, 8:00 AM EDT45°FENE 34 mph35°F13,793 ft8,543 ft above the summit
Sat, Sep 26, 2:00 PM EDT47°FENE 25 mph39°F13,077 ft7,828 ft above the summit
Sat, Sep 26, 8:00 PM EDT47°FENE 41 mph36°F12,733 ft7,484 ft above the summit
Sun, Sep 27, 2:00 AM EDT47°FE 50 mph35°F12,507 ft7,257 ft above the summit
Sun, Sep 27, 8:00 AM EDT47°FE 47 mph35°F12,635 ft7,385 ft above the summit
Sun, Sep 27, 2:00 PM EDT49°FE 44 mph39°F12,904 ft7,654 ft above the summit
Sun, Sep 27, 8:00 PM EDT49°FE 40 mph39°F12,890 ft7,641 ft above the summit
Mon, Sep 28, 2:00 AM EDT49°FESE 34 mph41°F12,123 ft6,873 ft above the summit
Mon, Sep 28, 8:00 AM EDT49°FESE 28 mph41°F12,047 ft6,798 ft above the summit
Mon, Sep 28, 2:00 PM EDT49°FESE 21 mph42°F11,467 ft6,217 ft above the summit
Mon, Sep 28, 8:00 PM EDT46°FE 23 mph38°F11,611 ft6,362 ft above the summit

NOAA’s GFS model, run Fri, Sep 25, 8:00 PM EDT, interpolated to 5,249 ft between its pressure levels: the free air over the summit, which on a ridge is close to what a climber feels and in a sheltered spot is more than it. Wind chill is the National Weather Service’s formula, given where the temperature is 50°F or less and the wind above 3 mph.

The National Weather Service forecast at the summit

PeriodTempWindForecast
OvernightLow 47°FE 15 mphMostly cloudy, with a low around 47. East wind around 15 mph, with gusts as high as 30 mph.
SaturdayHigh 56°FNE 15 mphA chance of rain after 3pm. Mostly cloudy, with a high near 56. Northeast wind around 15 mph, with gusts as high as 35 mph. Chance of precipitation is 30%. New rainfall amounts less than a tenth of an inch possible.
Saturday NightLow 46°FE 20-25 mphRain likely. Mostly cloudy, with a low around 46. East wind 20 to 25 mph, with gusts as high as 45 mph. Chance of precipitation is 70%. New rainfall amounts less than a tenth of an inch possible.
SundayHigh 49°FE 20-25 mphA chance of rain. Mostly cloudy, with a high near 49. East wind 20 to 25 mph, with gusts as high as 45 mph. Chance of precipitation is 50%.
Sunday NightLow 46°FE 15-20 mphRain likely. Mostly cloudy, with a low around 46. East wind 15 to 20 mph, with gusts as high as 40 mph. Chance of precipitation is 60%.
MondayHigh 48°FE 10-15 mphRain. Mostly cloudy, with a high near 48. Chance of precipitation is 80%.
Monday NightLow 46°FNE 10 mphRain. Cloudy, with a low around 46. Chance of precipitation is 80%.
TuesdayHigh 51°FN 5-10 mphA chance of rain before 9am. Mostly cloudy, with a high near 51. Chance of precipitation is 40%.
Tuesday NightLow 47°FNW 5 mphMostly cloudy, with a low around 47.
WednesdayHigh 57°FNW 5 mphMostly cloudy, with a high near 57.

The Weather Service’s forecast asked at the summit’s coordinates (44.1607, -71.6444), by its office in Gray - Portland, ME. Its grid cell is 2.5 km across and sits at 3,579 ft (1,091 m), 1,670 ft below the summit, so its temperatures and winds are for that height.

Cloud base and the summit

TimeSkyTemp and dew pointCloud base
Sat, Sep 26, 8:00 AM EDTMostly Cloudy48°F / 35°F6,545 ftBase above the summit
Sat, Sep 26, 2:00 PM EDTMostly Cloudy54°F / 39°F6,987 ftBase above the summit
Sat, Sep 26, 8:00 PM EDTLight Rain Likely50°F / 41°F5,630 ftBase above the summit
Sun, Sep 27, 2:00 AM EDTChance Light Rain48°F / 42°F4,951 ftSummit likely in cloud
Sun, Sep 27, 8:00 AM EDTSlight Chance Light Rain48°F / 41°F5,178 ftSummit likely in cloud
Sun, Sep 27, 2:00 PM EDTChance Light Rain47°F / 47°F3,579 ftSummit likely in cloud
Sun, Sep 27, 8:00 PM EDTLight Rain Likely48°F / 46°F4,039 ftSummit likely in cloud
Mon, Sep 28, 2:00 AM EDTLight Rain Likely48°F / 45°F4,267 ftSummit likely in cloud
Mon, Sep 28, 8:00 AM EDTLight Rain Likely46°F / 44°F4,044 ftSummit likely in cloud
Mon, Sep 28, 2:00 PM EDTLight Rain Likely48°F / 48°F3,584 ftSummit likely in cloud
Mon, Sep 28, 8:00 PM EDTLight Rain Likely48°F / 48°F3,584 ftSummit likely in cloud
Tue, Sep 29, 2:00 AM EDTLight Rain Likely48°F / 47°F3,811 ftSummit likely in cloud

An estimate: the height a rising parcel of the grid’s air would reach saturation, about 125 m for every degree Celsius between temperature and dew point (Espy’s rule), added to the grid’s ground. It fits cumulus and fog made on the spot, not a deck of stratus carried in from elsewhere.

Snow

No snow in the National Weather Service’s forecast for the summit’s grid cell over the next several days.

Sunrise and sunset

DayFirst lightSunriseSunsetLast lightDaylight
September 266:10 AM6:38 AM6:38 PM7:07 PM-12h 0m
September 276:11 AM6:40 AM6:36 PM7:05 PM-13h -4m
September 286:12 AM6:41 AM6:35 PM7:03 PM-13h -6m
September 296:13 AM6:42 AM6:33 PM7:02 PM-13h -9m
September 306:14 AM6:43 AM6:31 PM7:00 PM-13h -12m
October 16:16 AM6:44 AM6:29 PM6:58 PM-13h -15m
October 26:17 AM6:46 AM6:27 PM6:56 PM-13h -19m

For a sea-level horizon at the summit’s position, local time. From a summit the horizon sits lower, so the sun is seen a few minutes before sunrise and after sunset; a ridge to the east or west does the opposite.

Elevation
5,249 ft (1,600 m)
Prominence
3,320 ft (1,012 m)
Coordinates
44.1607, -71.6444
Nearest town
Deerfield

What this means

Why a summit forecast differs
The air cools with height, by about 3.6°F per 1,000 feet on average, and the wind above a ridge blows at the speed of the free atmosphere rather than slowed by the valley floor. A town’s forecast says little about the top of the mountain above it.
Freezing level
The height where the air is at 32°F (0°C). Above it precipitation falls as snow and wet rock freezes; the snow line usually sits a few hundred to a thousand feet below it.
Wind chill
How cold the air feels on exposed skin, from the temperature and the wind, by the National Weather Service’s 2001 formula.
Cloud base
Where cloud begins. When it is below the summit, the top is in cloud: no view, and in cold air, rime ice and poor visibility.
Prominence
How far a summit rises above the lowest contour line that encircles it and no higher summit: the measure of a mountain’s own height, not its neighbors’.

Nearby

Summits

Ski areas

Forecasts from the National Weather Service. Summit-height temperature, wind and freezing level from NOAA’s Global Forecast System on NOAA Open Data. Summits from Wikidata (CC0): prominence >= 600 m, or elevation >= 4267 m, or >= 12 Wikipedia editions; English Wikipedia article required; read 2026-09-25. Mountain weather changes fast; check the forecast again before you go.