Williston, North Dakota climate: Normal weather by month, frost dates and records
Williston's normal year runs from 1°F January nights to 85°F July afternoons, with 15.1 inches of precipitation and 48 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.4°C, January lows of −17°C, July highs of 29°C, 384 mm of precipitation a year.
- NOAA stationWilliston Sloulin Field
- Station IDUSW00094014
- Location48.17°N 103.64°W
- Elevation1,902 ft (580 m)
- Population28,821
On October 14, the normal high in Williston is 57°F and the normal low 31°F, and the chance of measurable rain or snow is 22%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Williston.
- Jan 22° 1°
- Feb 27° 6°
- Mar 40° 18°
- Apr 56° 29°
- May 67° 40°
- Jun 77° 50°
- Jul 85° 56°
- Aug 84° 54°
- Sep 73° 44°
- Oct 56° 30°
- Nov 38° 17°
- Dec 26° 6°
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 Williston each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 1°F. The most precipitation falls in June (2.64 in), the least in February (0.48 in).
Each month has its own page with the day-by-day normals, the month's records and its recent years:
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 22°F | 1°F | 11.6°F | 0.56 | 11.2 | 8 | <1 | 31 | 8 h 50 min |
| February | 27°F | 6°F | 16.1°F | 0.48 | 6.7 | 7 | <1 | 28 | 10 h 10 min |
| March | 40°F | 18°F | 28.8°F | 0.63 | 6.4 | 7 | <1 | 29 | 11 h 50 min |
| April | 56°F | 29°F | 42.4°F | 1.05 | 3.7 | 8 | <1 | 19 | 13 h 40 min |
| May | 67°F | 40°F | 53.8°F | 2.10 | 0.9 | 10 | <1 | 6 | 15 h 10 min |
| June | 77°F | 50°F | 63.5°F | 2.64 | 0.0 | 12 | 2 | <1 | 16 h |
| July | 85°F | 56°F | 70.4°F | 2.48 | 0.0 | 9 | 8 | <1 | 15 h 40 min |
| August | 84°F | 54°F | 69.0°F | 1.57 | 0.0 | 9 | 9 | <1 | 14 h 20 min |
| September | 73°F | 44°F | 58.0°F | 1.36 | 0.0 | 8 | 2 | 3 | 12 h 40 min |
| October | 56°F | 30°F | 43.2°F | 0.94 | 2.6 | 7 | <1 | 17 | 11 h |
| November | 38°F | 17°F | 27.8°F | 0.67 | 6.3 | 7 | <1 | 28 | 9 h 20 min |
| December | 26°F | 6°F | 16.1°F | 0.63 | 10.4 | 9 | <1 | 31 | 8 h 20 min |
| Year (annual) | 54°F | 29°F | 41.7°F | 15.11 | 48.2 | 100 | 21 | 191 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −5°C | −17°C | −11.3°C | 14 mm | 28 cm |
| February | −3°C | −15°C | −8.8°C | 12 mm | 17 cm |
| March | 5°C | −8°C | −1.8°C | 16 mm | 16 cm |
| April | 13°C | −2°C | 5.8°C | 27 mm | 9 cm |
| May | 20°C | 5°C | 12.1°C | 53 mm | 2 cm |
| June | 25°C | 10°C | 17.5°C | 67 mm | 0 cm |
| July | 29°C | 13°C | 21.3°C | 63 mm | 0 cm |
| August | 29°C | 12°C | 20.6°C | 40 mm | 0 cm |
| September | 23°C | 6°C | 14.4°C | 35 mm | 0 cm |
| October | 13°C | −1°C | 6.2°C | 24 mm | 7 cm |
| November | 4°C | −8°C | −2.3°C | 17 mm | 16 cm |
| December | −3°C | −14°C | −8.8°C | 16 mm | 26 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094014; 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 Williston?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (8).
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 USW00094014.
When is the last frost in Williston?
In Williston, the last spring frost (32°F) comes after May 21 in half of years and after June 3 in one year in ten; the first autumn frost comes before September 21 in half of years and before September 9 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 211 year in 10 after June 3; 9 in 10 after May 8
- First autumn frost, half of years before
- September 211 year in 10 before September 9; 9 in 10 before October 2
NOAA puts the median frost-free season at 123 days, and the season without a hard freeze (28°F) at 140 days.
A hard freeze (28°F) comes after May 11 in half of springs and before September 28 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Williston in zone 4a in ZIP code 58801, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Williston's NOAA station is in zone 4a: the coldest night of a typical year reaches −29°F (28 complete years).
Frost dates for every NOAA station in North Dakota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00094014; 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 Williston?
In a normal year in Williston, 21 days a year reach 90°F (2 of them 100°F or more), 191 nights fall to 32°F or colder and 100 days bring measurable precipitation.
- Days at 90°F or more
- 21a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 191a normal year
- Days that stay below freezing
- 80high of 32°F or less
- Days with 0.01 inch of precipitation
- 100a normal year
- Days with 1 inch of snow or more
- 14a normal year
The highest temperature in Williston's official record (kept by the National Weather Service since 1894) is 110°F, on July 5, 1936; the lowest is −50°F, on February 16, 1936.
The wettest calendar year on that record is 1896, with 22.04 in; the snowiest season is 2010–11, with 107.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00094014; records: ACIS (NOAA Regional Climate Centers), NWS threaded record ISNthr. Records use complete months only; a month missing more than three days is left out.
How humid and windy is Williston, and how clear are its skies?
The summer (June-August) dew point averages 52°F. The muggiest month is July, with an average dew point of 54°F; the driest air comes in December (7°F). April is the windiest month (10.5 mph on average), and July has the most clear or nearly clear hours (79%).
| Month | Dew point | Humidity | Afternoon humidity | Wind | Clear or few clouds | Overcast |
|---|---|---|---|---|---|---|
| January | 9°F | 78% | 67% | 8.3 mph | 56% | 32% |
| February | 12°F | 76% | 63% | 8.7 mph | 51% | 36% |
| March | 24°F | 63% | 43% | 9.9 mph | 57% | 29% |
| April | 33°F | 56% | 36% | 10.5 mph | 56% | 27% |
| May | 45°F | 61% | 42% | 9.7 mph | 57% | 25% |
| June | 53°F | 62% | 41% | 8.8 mph | 70% | 13% |
| July | 54°F | 58% | 35% | 7.9 mph | 79% | 8% |
| August | 48°F | 57% | 33% | 8.2 mph | 75% | 12% |
| September | 37°F | 61% | 38% | 8.6 mph | 70% | 18% |
| October | 26°F | 69% | 49% | 9.3 mph | 57% | 32% |
| November | 15°F | 77% | 65% | 8.2 mph | 52% | 37% |
| December | 7°F | 78% | 70% | 8.2 mph | 54% | 36% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00094014. Monthly averages of all hours; afternoon humidity at 3 p.m. local standard time; sky as the share of hours NOAA's observations rate clear or few clouds (a dash where NOAA publishes no sky value).
How sunny is Williston?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Williston, 3.9 kWh per square metre a day. July is the sunniest month (85%) and November the cloudiest (69%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 82% | 1.7 |
| February | 84% | 2.8 |
| March | 78% | 4.0 |
| April | 73% | 4.9 |
| May | 74% | 5.9 |
| June | 76% | 6.4 |
| July | 85% | 6.8 |
| August | 83% | 5.5 |
| September | 77% | 4.0 |
| October | 70% | 2.5 |
| November | 69% | 1.5 |
| December | 70% | 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 Williston need?
A normal year in Williston brings 8,906 heating degree days, 66% more than the median U.S. place (5,373), and 457 cooling degree days, 50% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,149 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,657 | 0 |
| February | 1,369 | 0 |
| March | 1,122 | 0 |
| April | 679 | 0 |
| May | 357 | 10 |
| June | 108 | 62 |
| July | 21 | 188 |
| August | 41 | 164 |
| September | 240 | 31 |
| October | 679 | 2 |
| November | 1,117 | 0 |
| December | 1,516 | 0 |
| Year (annual) | 8,906 | 457 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094014. 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 Williston been warmer than normal lately?
Over 134 complete years from 1879 to 2018, the station's annual mean temperature rose at a fitted 3.1°F per century (+0.17°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Williston's climate compare?
Williston is warmer than 56 of the other 91 places with their own NOAA record in North Dakota, and wetter than 1. Across the 7,247 U.S. stations with normals, its annual mean of 41.7°F is warmer than 9%.
In the Köppen classification computed from these normals, Williston 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.
Which places near Williston share this climate record?
5 places have no NOAA station with 1991-2020 normals of their own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Trenton, ND464 people · 12 mi SW
- Blacktail, ND107 people · 18 mi N
- Epping, ND87 people · 15 mi NE
- Springbrook, ND35 people · 10 mi NE
- Long Creek, ND23 people · 18 mi E
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
What do Williston's other NOAA stations record?
One more NOAA station keeps 1991-2020 normals in or near Williston. This page uses Williston Sloulin Field; the other differs by site and elevation:
| Station | From this station | Elevation | Year | Jan low | Jul high | Precip. | Snow | Last frost |
|---|---|---|---|---|---|---|---|---|
| Williston Experiment Farm USC00329430 | 5 mi SW | 2,105 ft | 43.4°F | 4°F | 85°F | 14.8 | 39 | May 13 |
Source: NOAA NCEI 1991-2020 normals for each station. Last frost: the median last spring date of 32°F.
Questions about Williston's climate
What is the coldest month in Williston?
January, with a normal high of 22°F and a normal low of 1°F. The warmest is July (85°F by day, 56°F at night).
Does it snow in Williston?
Yes: 48 inches in a normal year, falling on 43 days with 0.1 inch or more, the most in January (11.2 inches).
What is the rainiest month in Williston?
June, with 2.64 in of precipitation in a normal year; the driest is February with 0.48 in.
What plant hardiness zone is Williston in?
The USDA's 2023 map puts Williston in zone 4a in ZIP code 58801, the nearest ZIP area. By the same method at Williston's NOAA station, the coldest night of a typical year reaches −29°F (28 years, 1991-2020): zone 4a.
How late can frost come in Williston?
In half of years the last 32°F night comes after May 21; in one year in ten it comes after June 3. Waiting until June 3 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Williston in OctoberThis month day by day, its records and recent years
- North Dakota climateThe statewide normals and every place in the state
- Watford City, ND30 miles from this station, 42.1°F a year
- Tioga, ND37 miles from this station, 42.0°F a year
- Keene (3 mi S), ND39 miles from this station, 42.3°F a year
- Sidney, MT39 miles from this station, 45.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made