Mount Washington weather in September: Mount Washington, New Hampshire: normal highs, lows, rain and records for September
Mount Washington in September has a normal high of 49°F and a normal low of 37°F, a daily mean of 43°F, falling from 53°F on the 1st to 44°F by the 30th. Measurable precipitation falls on 14 days in a normal September, 7.66 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 10°C and low of 3°C, 195 mm of precipitation and 3 cm of snow in September.
- NOAA stationMount Washington
- Station IDUSW00014755
- Location44.27°N 71.30°W
- Elevation6,267 ft (1,910 m)
- Jan 15° -3°
- Feb 15° -3°
- Mar 21° 5°
- Apr 31° 17°
- May 43° 30°
- Jun 51° 40°
- Jul 55° 45°
- Aug 54° 43°
- Sep 49° 37°
- Oct 38° 25°
- Nov 28° 13°
- Dec 20° 4°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Mount Washington in September?
The normal high is 49°F and the normal low 37°F, for a daily mean of 43.1°F. September is 5.6°F cooler than August and 11.8°F warmer than October. September is the 4th warmest month of the year in Mount Washington and the 7th wettest. Across the month the normal high falls 9°F, from 53°F on September 1 to 44°F on September 30. From one year to the next September's mean temperature typically moves about 2.6°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 41°F and 46°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 51%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 53°F | 41°F | 46% | 34% |
| September 8 | 52°F | 40°F | 46% | 34% |
| September 15 | 50°F | 38°F | 47% | 35% |
| September 22 | 47°F | 35°F | 48% | 36% |
| September 30 | 44°F | 32°F | 51% | 37% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 53°F | 41°F | 46% | 34% | 13 h 20 min |
| September 2 | 53°F | 41°F | 46% | 34% | 13 h 10 min |
| September 3 | 53°F | 41°F | 46% | 34% | 13 h 10 min |
| September 4 | 53°F | 41°F | 46% | 34% | 13 h 10 min |
| September 5 | 52°F | 40°F | 46% | 34% | 13 h 10 min |
| September 6 | 52°F | 40°F | 46% | 34% | 13 h |
| September 7 | 52°F | 40°F | 46% | 34% | 13 h |
| September 8 | 52°F | 40°F | 46% | 34% | 13 h |
| September 9 | 51°F | 39°F | 46% | 34% | 12 h 50 min |
| September 10 | 51°F | 39°F | 46% | 35% | 12 h 50 min |
| September 11 | 51°F | 39°F | 47% | 35% | 12 h 50 min |
| September 12 | 51°F | 39°F | 47% | 35% | 12 h 40 min |
| September 13 | 50°F | 38°F | 47% | 35% | 12 h 40 min |
| September 14 | 50°F | 38°F | 47% | 35% | 12 h 40 min |
| September 15 | 50°F | 38°F | 47% | 35% | 12 h 40 min |
| September 16 | 49°F | 37°F | 47% | 35% | 12 h 30 min |
| September 17 | 49°F | 37°F | 47% | 35% | 12 h 30 min |
| September 18 | 49°F | 37°F | 47% | 35% | 12 h 30 min |
| September 19 | 48°F | 36°F | 47% | 35% | 12 h 20 min |
| September 20 | 48°F | 36°F | 47% | 35% | 12 h 20 min |
| September 21 | 48°F | 36°F | 48% | 36% | 12 h 20 min |
| September 22 | 47°F | 35°F | 48% | 36% | 12 h 10 min |
| September 23 | 47°F | 35°F | 48% | 36% | 12 h 10 min |
| September 24 | 46°F | 34°F | 49% | 36% | 12 h 10 min |
| September 25 | 46°F | 34°F | 49% | 36% | 12 h 10 min |
| September 26 | 46°F | 34°F | 49% | 37% | 12 h |
| September 27 | 45°F | 33°F | 50% | 37% | 12 h |
| September 28 | 45°F | 33°F | 50% | 37% | 12 h |
| September 29 | 44°F | 32°F | 51% | 37% | 11 h 50 min |
| September 30 | 44°F | 32°F | 51% | 37% | 11 h 50 min |
- Normal high
- 49°FSeptember average
- Normal low
- 37°FSeptember average
- Precipitation
- 7.66 inmonth total
- Days with precipitation
- 140.01 inch or more
- Snowfall
- 1.2 inmonth total
- Nights at 32°F or colder
- 9
- Daylight
- 13 h 20 min to 11 h 50 minSeptember 1 to September 30
- Sunshine
- 73%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00014755; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in Mount Washington in September?
On a given September day the chance of 0.01 inch or more is 47% on average, highest around September 30 (51%). In all, 7.66 in falls on 14 days of a normal September, 2 of them with an inch or more.
In a normal September in Mount Washington, 9 nights fall to freezing, 1 days stay below freezing all day and snowfall averages 1.2 inches.
Snow falls on 1 day in a normal September.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00014755.
What are the records for September in Mount Washington?
The warmest September temperature on this station's record (since 1948) is 69°F, on September 3, 1999; the coldest is 9°F, on September 30, 1992. The wettest September brought 18.82 in (1999); the snowiest, 7.8 inches (1949).
The September mean against the 1991-2020 normal of 43.1°F: 2021 43.1°F (at normal), 2022 42.8°F (−0.3), 2023 47.4°F (+4.3), 2024 44.9°F (+1.8), 2026 41.6°F (−1.5). 2 of 5 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 43.1°F | at normal | 10.47 in |
| 2022 | 42.8°F | −0.3°F | 11.45 in |
| 2023 | 47.4°F | +4.3°F | 9.00 in |
| 2024 | 44.9°F | +1.8°F | 4.02 in |
| 2026 | 41.6°F | −1.5°F | 4.03 in |
Source: records: ACIS, station USW00014755; recent months: ACIS, station USW00014755. Records and recent months use complete months only.
How does September in Mount Washington compare across New Hampshire?
Across the 28 places PlainClimate covers in New Hampshire, September normal highs run from 68°F in Colebrook to 75°F in Nashua; Mount Washington's is 49°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Mount Washington in August54°F by day, 43°F at night
- Mount Washington in October38°F by day, 25°F at night
- Mount Washington through the yearEvery month, frost dates, records and recent years
- New Hampshire in SeptemberThe statewide normal and the warmest and coolest places
- Nashua: New Hampshire's warmest Septembernormal high 75°F