Grafton, North Dakota climate: Normal weather by month, frost dates and records
Grafton's normal year runs from 0°F January nights to 81°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.6°C, January lows of −18°C, July highs of 27°C.
- NOAA stationGrafton
- Station IDUSC00323594
- Location48.42°N 97.42°W
- Elevation827 ft (252 m)
- From the centerunder 1 mile
- Population4,027
On October 23, the normal high in Grafton is 49°F and the normal low 33°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Grafton.
- Jan 16° 0°
- Feb 21° 4°
- Mar 34° 19°
- Apr 53° 33°
- May 68° 46°
- Jun 79° 57°
- Jul 81° 61°
- Aug 80° 59°
- Sep 71° 50°
- Oct 54° 36°
- Nov 36° 22°
- Dec 21° 7°
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 Grafton each month?
July is the warmest month, with normal highs of 81°F; January the coldest, with normal lows of 0°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 16°F | 0°F | 7.7°F | – | <1 | 31 | 8 h 40 min |
| February | 21°F | 4°F | 12.6°F | – | <1 | 27 | 10 h 10 min |
| March | 34°F | 19°F | 26.4°F | – | <1 | 26 | 11 h 50 min |
| April | 53°F | 33°F | 42.8°F | – | <1 | 14 | 13 h 40 min |
| May | 68°F | 46°F | 57.3°F | – | 1 | 2 | 15 h 10 min |
| June | 79°F | 57°F | 68.0°F | – | 2 | <1 | 16 h |
| July | 81°F | 61°F | 71.3°F | – | 2 | <1 | 15 h 40 min |
| August | 80°F | 59°F | 69.6°F | – | 4 | <1 | 14 h 20 min |
| September | 71°F | 50°F | 60.6°F | – | 1 | 1 | 12 h 40 min |
| October | 54°F | 36°F | 45.1°F | – | <1 | 11 | 11 h |
| November | 36°F | 22°F | 28.7°F | – | <1 | 27 | 9 h 20 min |
| December | 21°F | 7°F | 14.0°F | – | <1 | 31 | 8 h 20 min |
| Year (annual) | 51°F | 33°F | 42.0°F | – | 10 | 169 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | −9°C | −18°C | −13.5°C |
| February | −6°C | −15°C | −10.8°C |
| March | 1°C | −7°C | −3.1°C |
| April | 11°C | 1°C | 6.0°C |
| May | 20°C | 8°C | 14.1°C |
| June | 26°C | 14°C | 20.0°C |
| July | 27°C | 16°C | 21.8°C |
| August | 27°C | 15°C | 20.9°C |
| September | 22°C | 10°C | 15.9°C |
| October | 12°C | 2°C | 7.3°C |
| November | 2°C | −6°C | −1.8°C |
| December | −6°C | −14°C | −10.0°C |
NOAA publishes no 1991-2020 snowfall normal for this station, and no record within 25 miles keeps one, so snow is left out here rather than estimated.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00323594; 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 Grafton?
Normal highs sit between 65°F and 85°F in May, June, July, August and September.
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 USC00323594.
When is the last frost in Grafton?
In Grafton, the last spring frost (32°F) comes after May 4 in half of years and after May 18 in one year in ten; the first autumn frost comes before October 7 in half of years and before September 25 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 41 year in 10 after May 18; 9 in 10 after April 19
- First autumn frost, half of years before
- October 71 year in 10 before September 25; 9 in 10 before October 21
NOAA puts the median frost-free season at 156 days, and the season without a hard freeze (28°F) at 174 days.
A hard freeze (28°F) comes after April 24 in half of springs and before October 17 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Grafton in zone 4a in ZIP code 58237, the nearest ZIP area.
Frost dates for every NOAA station in North Dakota · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00323594; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 Grafton?
In a normal year in Grafton, 10 days a year reach 90°F and 169 nights fall to 32°F or colder.
- Days at 90°F or more
- 10a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 169a normal year
- Days that stay below freezing
- 101high of 32°F or less
The highest temperature in this station's record (since 1893) is 108°F, on July 11, 1936; the lowest is −47°F, on February 11, 1914.
The wettest calendar year on that record is 1941, with 26.66 in; the snowiest season is 1955–56, with 72.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00323594; records: ACIS (NOAA Regional Climate Centers), station USC00323594. Records use complete months only; a month missing more than three days is left out.
How sunny is Grafton?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Grafton, 3.8 kWh per square metre a day. February is the sunniest month (87%) and November the cloudiest (64%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 80% | 1.6 |
| February | 87% | 2.9 |
| March | 80% | 4.0 |
| April | 73% | 4.8 |
| May | 71% | 5.6 |
| June | 73% | 6.0 |
| July | 81% | 6.3 |
| August | 80% | 5.3 |
| September | 75% | 3.8 |
| October | 67% | 2.4 |
| November | 64% | 1.4 |
| December | 65% | 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 Grafton need?
A normal year in Grafton brings 8,950 heating degree days, 67% more than the median U.S. place (5,373), and 611 cooling degree days, 33% 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 2,527 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,776 | 0 |
| February | 1,467 | 0 |
| March | 1,195 | 0 |
| April | 668 | 2 |
| May | 277 | 36 |
| June | 51 | 139 |
| July | 12 | 206 |
| August | 31 | 173 |
| September | 184 | 52 |
| October | 620 | 3 |
| November | 1,089 | 0 |
| December | 1,581 | 0 |
| Year (annual) | 8,950 | 611 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00323594. 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 Grafton's climate compare?
Grafton is warmer than 58 of the other 91 places with their own NOAA record in North Dakota. Across the 7,247 U.S. stations with normals, its annual mean of 42.0°F is warmer than 9%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near Grafton share this climate record?
12 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.
- Park River, ND1,369 people · 15 mi W
- Minto, ND608 people · 9 mi S
- St. Thomas, ND307 people · 14 mi N
- Hoople, ND242 people · 13 mi NW
- Edinburg, ND192 people · 21 mi W
- Crystal, ND111 people · 17 mi NW
- Forest River, ND111 people · 14 mi S
- Pisek, ND86 people · 15 mi SW
- Ardoch, ND32 people · 15 mi S
- Conway, ND14 people · 17 mi SW
- Auburn, ND13 people · 6 mi N
- Nash, ND9 people · 6 mi NW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Grafton's climate
What is the coldest month in Grafton?
January, with a normal high of 16°F and a normal low of 0°F. The warmest is July (81°F by day, 61°F at night).
What plant hardiness zone is Grafton in?
The USDA's 2023 map puts Grafton in zone 4a in ZIP code 58237, the nearest ZIP area.
How late can frost come in Grafton?
In half of years the last 32°F night comes after May 4; in one year in ten it comes after May 18. Waiting until May 18 leaves about a one-in-ten chance of a later frost.
Nearby and next
- North Dakota climateThe statewide normals and every place in the state
- Argyle, MN28 miles from this station, 39.5°F a year
- Hallock, MN33 miles from this station, 39.1°F a year
- Cavalier, ND33 miles from this station, 38.1°F a year
- Warren, MN34 miles from this station, 39.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made