Fort Peck, Montana climate: Normal weather by month, frost dates and records
Fort Peck's normal year runs from 8°F January nights to 89°F July afternoons, with 13.6 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 8.1°C, January lows of −14°C, July highs of 31°C, 345 mm of precipitation a year.
- NOAA stationFort Peck Power Plant
- Station IDUSC00243176
- Location48.01°N 106.41°W
- Elevation2,071 ft (631 m)
- Population234
On October 14, the normal high in Fort Peck is 62°F and the normal low 38°F, and the chance of measurable rain or snow is 18%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fort Peck.
- Jan 28° 8°
- Feb 33° 12°
- Mar 46° 22°
- Apr 60° 34°
- May 71° 44°
- Jun 80° 53°
- Jul 89° 59°
- Aug 88° 57°
- Sep 77° 48°
- Oct 61° 37°
- Nov 44° 24°
- Dec 32° 13°
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 Peck each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 8°F. The most precipitation falls in June (2.67 in), the least in January (0.30 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 28°F | 8°F | 17.9°F | 0.30 | 5 | <1 | 30 | 8 h 50 min |
| February | 33°F | 12°F | 22.4°F | 0.30 | 4 | <1 | 27 | 10 h 10 min |
| March | 46°F | 22°F | 34.3°F | 0.38 | 4 | <1 | 26 | 11 h 50 min |
| April | 60°F | 34°F | 46.9°F | 0.92 | 6 | <1 | 14 | 13 h 40 min |
| May | 71°F | 44°F | 57.2°F | 2.52 | 10 | 1 | 3 | 15 h 10 min |
| June | 80°F | 53°F | 66.3°F | 2.67 | 11 | 4 | <1 | 16 h |
| July | 89°F | 59°F | 73.5°F | 2.39 | 8 | 15 | <1 | 15 h 40 min |
| August | 88°F | 57°F | 72.6°F | 1.40 | 6 | 15 | <1 | 14 h 20 min |
| September | 77°F | 48°F | 62.1°F | 1.05 | 6 | 3 | 1 | 12 h 40 min |
| October | 61°F | 37°F | 48.8°F | 0.94 | 6 | <1 | 10 | 11 h |
| November | 44°F | 24°F | 33.9°F | 0.36 | 4 | <1 | 24 | 9 h 20 min |
| December | 32°F | 13°F | 22.4°F | 0.35 | 5 | <1 | 29 | 8 h 20 min |
| Year (annual) | 59°F | 34°F | 46.5°F | 13.58 | 73 | 38 | 164 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | −2°C | −14°C | −7.8°C | 8 mm |
| February | 1°C | −11°C | −5.3°C | 8 mm |
| March | 8°C | −5°C | 1.3°C | 10 mm |
| April | 16°C | 1°C | 8.3°C | 23 mm |
| May | 22°C | 7°C | 14.0°C | 64 mm |
| June | 26°C | 12°C | 19.1°C | 68 mm |
| July | 31°C | 15°C | 23.1°C | 61 mm |
| August | 31°C | 14°C | 22.6°C | 36 mm |
| September | 25°C | 9°C | 16.7°C | 27 mm |
| October | 16°C | 3°C | 9.3°C | 24 mm |
| November | 7°C | −5°C | 1.1°C | 9 mm |
| December | 0°C | −11°C | −5.3°C | 9 mm |
NOAA publishes no 1991-2020 snowfall normal for this station. The nearest record that keeps one, Glasgow (17 miles away), gets 41 inches of snow in a normal year; elevation and distance can change that.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00243176; 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 Peck?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (6).
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 USC00243176.
When is the last frost in Fort Peck?
In Fort Peck, the last spring frost (32°F) comes after May 8 in half of years and after May 20 in one year in ten; the first autumn frost comes before October 1 in half of years and before September 18 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
- May 81 year in 10 after May 20; 9 in 10 after April 25
- First autumn frost, half of years before
- October 11 year in 10 before September 18; 9 in 10 before October 16
NOAA puts the median frost-free season at 145 days, and the season without a hard freeze (28°F) at 166 days.
A hard freeze (28°F) comes after April 28 in half of springs and before October 10 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fort Peck in zone 4a in ZIP code 59223, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Fort Peck's NOAA station is in zone 4b: the coldest night of a typical year reaches −24°F (20 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Montana · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00243176; 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 Peck?
In a normal year in Fort Peck, 38 days a year reach 90°F (4 of them 100°F or more), 164 nights fall to 32°F or colder and 73 days bring measurable precipitation.
- Days at 90°F or more
- 38a normal year
- Days at 100°F or more
- 4a normal year
- Nights at 32°F or colder
- 164a normal year
- Days that stay below freezing
- 55high of 32°F or less
- Days with 0.01 inch of precipitation
- 73a normal year
The highest temperature in this station's record (since 1956) is 110°F, on August 8, 1995; the lowest is −42°F, on January 25, 1969.
The wettest calendar year on that record is 1965, with 21.29 in; the snowiest season is 2022–23, with 36.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00243176; records: ACIS (NOAA Regional Climate Centers), station USC00243176. Records use complete months only; a month missing more than three days is left out.
How sunny is Fort Peck?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fort Peck, 4.0 kWh per square metre a day. July is the sunniest month (86%) and December the cloudiest (68%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 1.5 |
| February | 78% | 2.6 |
| March | 75% | 3.8 |
| April | 73% | 4.9 |
| May | 75% | 6.0 |
| June | 77% | 6.5 |
| July | 86% | 6.9 |
| August | 85% | 5.7 |
| September | 79% | 4.2 |
| October | 75% | 2.7 |
| November | 72% | 1.6 |
| December | 68% | 1.1 |
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 Peck need?
A normal year in Fort Peck brings 7,403 heating degree days, 38% more than the median U.S. place (5,373), and 707 cooling degree days, 22% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,728 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,460 | 0 |
| February | 1,193 | 0 |
| March | 952 | 0 |
| April | 546 | 1 |
| May | 261 | 20 |
| June | 59 | 98 |
| July | 9 | 273 |
| August | 17 | 251 |
| September | 146 | 59 |
| October | 508 | 4 |
| November | 933 | 0 |
| December | 1,321 | 0 |
| Year (annual) | 7,403 | 707 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00243176. 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.
Has Fort Peck been warmer than normal lately?
2025 averaged 46.7°F, 0.2°F above the 1991-2020 normal of 46.5°F. 2 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 48.1°F | +1.6°F | 6.16 |
| 2025 | 46.7°F | +0.2°F | 10.59 |
Over 46 complete years from 1957 to 2025, the station's annual mean temperature rose at a fitted 4.9°F per century (+0.27°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00243176; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Fort Peck's climate compare?
Fort Peck is warmer than 121 of the other 140 places with their own NOAA record in Montana, and wetter than 45. Across the 7,247 U.S. stations with normals, its annual mean of 46.5°F is warmer than 25%.
In the Köppen classification computed from these normals, Fort Peck 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 Peck's climate
What is the coldest month in Fort Peck?
January, with a normal high of 28°F and a normal low of 8°F. The warmest is July (89°F by day, 59°F at night).
Does it snow in Fort Peck?
Yes. NOAA publishes no 1991-2020 snowfall normal for Fort Peck's NOAA station; the nearest record that keeps one, Glasgow (17 miles away), records 41 inches of snow in a normal year.
What is the rainiest month in Fort Peck?
June, with 2.67 in of precipitation in a normal year; the driest is January with 0.30 in.
What plant hardiness zone is Fort Peck in?
The USDA's 2023 map puts Fort Peck in zone 4a in ZIP code 59223, the nearest ZIP area. By the same method at Fort Peck's NOAA station, the coldest night of a typical year reaches −24°F (20 years, 1991-2020): zone 4b.
How late can frost come in Fort Peck?
In half of years the last 32°F night comes after May 8; in one year in ten it comes after May 20. Waiting until May 20 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Montana climateThe statewide normals and every place in the state
- Nashua, MT9 miles from this station, 44.3°F a year
- Glasgow, MT17 miles from this station, 43.9°F a year
- St. Marie, MT28 miles from this station, 43.0°F a year
- Wolf Point, MT39 miles from this station, 43.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made