Fortuna, North Dakota climate: Normal weather by month, frost dates and records
Fortuna's normal year runs from −2°F January nights to 80°F July afternoons, with 15.3 inches of precipitation and 37 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 3.5°C, January lows of −19°C, July highs of 26°C, 389 mm of precipitation a year.
- NOAA stationFortuna (1 mi W)
- Station IDUSC00323196
- Location48.91°N 103.81°W
- Elevation2,350 ft (716 m)
- Population30
On October 22, the normal high in Fortuna is 49°F and the normal low 25°F, and the chance of measurable rain or snow is 8%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fortuna.
- Jan 17° -2°
- Feb 21° 2°
- Mar 34° 14°
- Apr 52° 27°
- May 65° 39°
- Jun 73° 49°
- Jul 80° 54°
- Aug 80° 52°
- Sep 69° 41°
- Oct 53° 28°
- Nov 35° 15°
- Dec 22° 3°
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 Fortuna each month?
July is the warmest month, with normal highs of 80°F; January the coldest, with normal lows of −2°F. The most precipitation falls in June (3.30 in), the least in February (0.46 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 17°F | −2°F | 7.3°F | 0.62 | 6.6 | 2 | <1 | 31 | 8 h 40 min |
| February | 21°F | 2°F | 11.6°F | 0.46 | 5.7 | 2 | <1 | 28 | 10 h 10 min |
| March | 34°F | 14°F | 24.0°F | 0.62 | 7.0 | 3 | <1 | 30 | 11 h 50 min |
| April | 52°F | 27°F | 39.2°F | 1.15 | 3.4 | 3 | <1 | 22 | 13 h 40 min |
| May | 65°F | 39°F | 51.7°F | 2.06 | 0.9 | 6 | <1 | 7 | 15 h 10 min |
| June | 73°F | 49°F | 61.1°F | 3.30 | 0.0 | 10 | 1 | <1 | 16 h 10 min |
| July | 80°F | 54°F | 66.8°F | 2.43 | 0.0 | 7 | 4 | <1 | 15 h 50 min |
| August | 80°F | 52°F | 65.7°F | 1.46 | 0.0 | 5 | 5 | <1 | 14 h 30 min |
| September | 69°F | 41°F | 55.0°F | 1.18 | 0.0 | 3 | 1 | 4 | 12 h 40 min |
| October | 53°F | 28°F | 40.2°F | 1.03 | 2.2 | 3 | <1 | 21 | 10 h 50 min |
| November | 35°F | 15°F | 24.7°F | 0.54 | 4.3 | 2 | <1 | 29 | 9 h 10 min |
| December | 22°F | 3°F | 12.9°F | 0.48 | 6.4 | 3 | <1 | 31 | 8 h 20 min |
| Year (annual) | 50°F | 27°F | 38.3°F | 15.33 | 36.5 | 48 | 10 | 204 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −8°C | −19°C | −13.7°C | 16 mm | 17 cm |
| February | −6°C | −17°C | −11.3°C | 12 mm | 14 cm |
| March | 1°C | −10°C | −4.4°C | 16 mm | 18 cm |
| April | 11°C | −3°C | 4.0°C | 29 mm | 9 cm |
| May | 18°C | 4°C | 10.9°C | 52 mm | 2 cm |
| June | 23°C | 10°C | 16.2°C | 84 mm | 0 cm |
| July | 26°C | 12°C | 19.3°C | 62 mm | 0 cm |
| August | 27°C | 11°C | 18.7°C | 37 mm | 0 cm |
| September | 21°C | 5°C | 12.8°C | 30 mm | 0 cm |
| October | 11°C | −2°C | 4.6°C | 26 mm | 6 cm |
| November | 1°C | −10°C | −4.1°C | 14 mm | 11 cm |
| December | −5°C | −16°C | −10.6°C | 12 mm | 16 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00323196; 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 Fortuna?
Normal highs sit between 65°F and 85°F in June, July, August and September. Of those, September has the fewest days with rain (3).
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 USC00323196.
When is the last frost in Fortuna?
In Fortuna, the last spring frost (32°F) comes after May 19 in half of years and after May 31 in one year in ten; the first autumn frost comes before September 17 in half of years and before September 4 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 191 year in 10 after May 31; 9 in 10 after May 8
- First autumn frost, half of years before
- September 171 year in 10 before September 4; 9 in 10 before September 28
NOAA puts the median frost-free season at 121 days, and the season without a hard freeze (28°F) at 138 days.
A hard freeze (28°F) comes after May 10 in half of springs and before September 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fortuna in zone 3b in ZIP code 58844, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Fortuna's NOAA station is in zone 3b: the coldest night of a typical year reaches −32°F (20 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 USC00323196; 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 Fortuna?
In a normal year in Fortuna, 10 days a year reach 90°F, 204 nights fall to 32°F or colder and 48 days bring measurable precipitation.
- 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
- 204a normal year
- Days that stay below freezing
- 100high of 32°F or less
- Days with 0.01 inch of precipitation
- 48a normal year
- Days with 1 inch of snow or more
- 12a normal year
The highest temperature in this station's record (since 1963) is 106°F, on July 25, 2007; the lowest is −45°F, on December 23, 1983.
The wettest calendar year on that record is 1978, with 25.59 in; the snowiest season is 2008–09, with 65.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00323196; records: ACIS (NOAA Regional Climate Centers), station USC00323196. Records use complete months only; a month missing more than three days is left out.
How sunny is Fortuna?
Over a year 77% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fortuna, 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 Fortuna need?
A normal year in Fortuna brings 9,958 heating degree days, 85% more than the median U.S. place (5,373), and 278 cooling degree days, 69% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,744 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,789 | 0 |
| February | 1,497 | 0 |
| March | 1,270 | 0 |
| April | 776 | 0 |
| May | 418 | 6 |
| June | 156 | 39 |
| July | 56 | 111 |
| August | 81 | 103 |
| September | 320 | 19 |
| October | 771 | 1 |
| November | 1,211 | 0 |
| December | 1,615 | 0 |
| Year (annual) | 9,958 | 278 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00323196. 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 Fortuna been warmer than normal lately?
Over 31 complete years from 1964 to 2021, the station's annual mean temperature rose at a fitted 4.7°F per century (+0.26°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 Fortuna's climate compare?
Fortuna is warmer than 8 of the other 91 places with their own NOAA record in North Dakota, and wetter than 2. Across the 7,247 U.S. stations with normals, its annual mean of 38.3°F is warmer than 3%.
In the Köppen classification computed from these normals, Fortuna is Dfb: continental, no dry season, warm summer. 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 Fortuna's climate
What is the coldest month in Fortuna?
January, with a normal high of 17°F and a normal low of −2°F. The warmest is July (80°F by day, 54°F at night).
Does it snow in Fortuna?
Yes: 37 inches in a normal year, falling on 13 days with 0.1 inch or more, the most in March (7.0 inches).
What is the rainiest month in Fortuna?
June, with 3.30 in of precipitation in a normal year; the driest is February with 0.46 in.
What plant hardiness zone is Fortuna in?
The USDA's 2023 map puts Fortuna in zone 3b in ZIP code 58844, the nearest ZIP area. By the same method at Fortuna's NOAA station, the coldest night of a typical year reaches −32°F (20 years, 1991-2020): zone 3b.
How late can frost come in Fortuna?
In half of years the last 32°F night comes after May 19; in one year in ten it comes after May 31. Waiting until May 31 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
- Westby, MT11 miles from this station, 39.1°F a year
- Crosby, ND23 miles from this station, 40.2°F a year
- Wildrose, ND32 miles from this station, 38.8°F a year
- Raymond Border Station, MT35 miles from this station, 40.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made