Fort Sumner, New Mexico climate: Normal weather by month, frost dates and records
Fort Sumner's normal year runs from 25°F January nights to 92°F July afternoons, with 15.1 inches of precipitation and 9 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 15.1°C, January lows of −4°C, July highs of 33°C, 383 mm of precipitation a year.
- NOAA stationFort Sumner
- Station IDUSC00293294
- Location34.47°N 104.23°W
- Elevation4,025 ft (1,227 m)
- Population857
On October 23, the normal high in Fort Sumner is 72°F and the normal low 42°F, and the chance of measurable rain or snow is 14%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fort Sumner.
- Jan 55° 25°
- Feb 60° 28°
- Mar 67° 35°
- Apr 74° 43°
- May 82° 52°
- Jun 91° 62°
- Jul 92° 66°
- Aug 90° 65°
- Sep 84° 57°
- Oct 74° 44°
- Nov 63° 33°
- Dec 55° 25°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Fort Sumner each month?
July is the warmest month, with normal highs of 92°F; January the coldest, with normal lows of 25°F. The most precipitation falls in July (2.56 in), the least in November (0.39 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 55°F | 25°F | 39.7°F | 0.45 | 3.0 | 3 | <1 | 28 | 10 h |
| February | 60°F | 28°F | 43.9°F | 0.49 | 1.3 | 4 | <1 | 22 | 11 h |
| March | 67°F | 35°F | 51.4°F | 0.69 | 1.0 | 5 | <1 | 14 | 11 h 50 min |
| April | 74°F | 43°F | 58.6°F | 1.44 | 0.2 | 4 | 1 | 4 | 13 h |
| May | 82°F | 52°F | 67.1°F | 1.17 | 0.0 | 5 | 6 | <1 | 14 h |
| June | 91°F | 62°F | 76.4°F | 1.46 | 0.0 | 6 | 17 | <1 | 14 h 30 min |
| July | 92°F | 66°F | 79.0°F | 2.56 | 0.0 | 8 | 21 | <1 | 14 h 20 min |
| August | 90°F | 65°F | 77.2°F | 2.31 | 0.0 | 8 | 17 | <1 | 13 h 30 min |
| September | 84°F | 57°F | 70.2°F | 1.63 | 0.0 | 6 | 6 | <1 | 12 h 30 min |
| October | 74°F | 44°F | 59.3°F | 1.87 | 0.3 | 5 | <1 | 3 | 11 h 20 min |
| November | 63°F | 33°F | 47.9°F | 0.39 | 0.7 | 3 | <1 | 18 | 10 h 20 min |
| December | 55°F | 25°F | 39.8°F | 0.62 | 2.6 | 4 | <1 | 27 | 9 h 50 min |
| Year (annual) | 74°F | 45°F | 59.2°F | 15.08 | 9.1 | 62 | 68 | 114 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 13°C | −4°C | 4.3°C | 11 mm | 8 cm |
| February | 15°C | −2°C | 6.6°C | 12 mm | 3 cm |
| March | 20°C | 2°C | 10.8°C | 18 mm | 3 cm |
| April | 23°C | 6°C | 14.8°C | 37 mm | 1 cm |
| May | 28°C | 11°C | 19.5°C | 30 mm | 0 cm |
| June | 33°C | 17°C | 24.7°C | 37 mm | 0 cm |
| July | 33°C | 19°C | 26.1°C | 65 mm | 0 cm |
| August | 32°C | 18°C | 25.1°C | 59 mm | 0 cm |
| September | 29°C | 14°C | 21.2°C | 41 mm | 0 cm |
| October | 24°C | 7°C | 15.2°C | 47 mm | 1 cm |
| November | 17°C | 0°C | 8.8°C | 10 mm | 2 cm |
| December | 13°C | −4°C | 4.3°C | 16 mm | 7 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00293294; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
When is the best weather to visit Fort Sumner?
Normal highs sit between 65°F and 85°F in March, April, May, September and October. Of those, April has the fewest days with rain (4).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00293294.
When is the last frost in Fort Sumner?
In Fort Sumner, the last spring frost (32°F) comes after April 9 in half of years and after April 25 in one year in ten; the first autumn frost comes before October 30 in half of years and before October 16 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- April 91 year in 10 after April 25; 9 in 10 after March 24
- First autumn frost, half of years before
- October 301 year in 10 before October 16; 9 in 10 before November 9
NOAA puts the median frost-free season at 201 days, and the season without a hard freeze (28°F) at 224 days.
A hard freeze (28°F) comes after March 26 in half of springs and before November 6 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fort Sumner in zone 7a in ZIP code 88119, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Fort Sumner's NOAA station is in zone 7a: the coldest night of a typical year reaches 5°F (17 complete years).
Frost dates for every NOAA station in New Mexico · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00293294; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get in Fort Sumner?
In a normal year in Fort Sumner, 68 days a year reach 90°F (4 of them 100°F or more), 114 nights fall to 32°F or colder and 62 days bring measurable precipitation.
- Days at 90°F or more
- 68a normal year
- Days at 100°F or more
- 4a normal year
- Nights at 32°F or colder
- 114a normal year
- Days that stay below freezing
- 4high of 32°F or less
- Days with 0.01 inch of precipitation
- 62a normal year
- Days with 1 inch of snow or more
- 4a normal year
The highest temperature in this station's record (since 1908) is 109°F, on June 29, 1918; the lowest is −27°F, on January 13, 1963.
The wettest calendar year on that record is 1919, with 30.51 in; the snowiest season is 1918–19, with 57.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00293294; records: ACIS (NOAA Regional Climate Centers), station USC00293294. Records use complete months only; a month missing more than three days is left out.
How sunny is Fort Sumner?
Over a year 87% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fort Sumner, 5.6 kWh per square metre a day. June is the sunniest month (90%) and December the cloudiest (84%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 86% | 3.4 |
| February | 84% | 4.3 |
| March | 85% | 5.6 |
| April | 87% | 6.9 |
| May | 87% | 7.6 |
| June | 90% | 7.9 |
| July | 88% | 7.4 |
| August | 87% | 6.7 |
| September | 87% | 5.8 |
| October | 86% | 4.6 |
| November | 86% | 3.6 |
| December | 84% | 3.0 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How much heating and cooling does Fort Sumner need?
A normal year in Fort Sumner brings 3,588 heating degree days, 33% fewer than the median U.S. place (5,373), and 1,504 cooling degree days, 66% more than the median (908). Five months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 4,509 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 783 | 0 |
| February | 591 | 0 |
| March | 424 | 3 |
| April | 214 | 20 |
| May | 56 | 121 |
| June | 1 | 343 |
| July | 0 | 433 |
| August | 0 | 380 |
| September | 25 | 181 |
| October | 198 | 23 |
| November | 515 | 1 |
| December | 781 | 0 |
| Year (annual) | 3,588 | 1,504 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00293294. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
How does Fort Sumner's climate compare?
Fort Sumner is warmer than 74 of the other 97 places with their own NOAA record in New Mexico, and wetter than 58. Across the 7,247 U.S. stations with normals, its annual mean of 59.2°F is warmer than 72%.
In the Köppen classification computed from these normals, Fort Sumner is BSk: cold semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Questions about Fort Sumner's climate
What is the coldest month in Fort Sumner?
January, with a normal high of 55°F and a normal low of 25°F. The warmest is July (92°F by day, 66°F at night).
Does it snow in Fort Sumner?
Yes: 9 inches in a normal year, falling on 5 days with 0.1 inch or more, the most in January (3.0 inches).
What is the rainiest month in Fort Sumner?
July, with 2.56 in of precipitation in a normal year; the driest is November with 0.39 in.
What plant hardiness zone is Fort Sumner in?
The USDA's 2023 map puts Fort Sumner in zone 7a in ZIP code 88119, the nearest ZIP area. By the same method at Fort Sumner's NOAA station, the coldest night of a typical year reaches 5°F (17 years, 1991-2020): zone 7a.
How late can frost come in Fort Sumner?
In half of years the last 32°F night comes after April 9; in one year in ten it comes after April 25. Waiting until April 25 leaves about a one-in-ten chance of a later frost.
Nearby and next
- New Mexico climateThe statewide normals and every place in the state
- Fort Sumner (5 mi S), NM5 miles from this station, 59.3°F a year
- Sumner Lake, NM12 miles from this station, 59.7°F a year
- Yeso (2 mi S), NM22 miles from this station, 58.2°F a year
- Melrose, NM35 miles from this station, 59.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made