Fort Supply, Oklahoma climate: Normal weather by month, frost dates and records
Fort Supply's normal year runs from 20°F January nights to 94°F July afternoons, with 25.2 inches of precipitation and 12 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 13.8°C, January lows of −7°C, July highs of 34°C, 641 mm of precipitation a year.
- NOAA stationFort Supply (3 mi SE)
- Station IDUSC00343304
- Location36.54°N 99.53°W
- Elevation2,030 ft (619 m)
- Population319
On October 23, the normal high in Fort Supply is 70°F and the normal low 40°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 Supply.
- Jan 48° 20°
- Feb 52° 23°
- Mar 62° 32°
- Apr 71° 41°
- May 79° 52°
- Jun 88° 63°
- Jul 94° 68°
- Aug 93° 65°
- Sep 85° 56°
- Oct 73° 43°
- Nov 60° 30°
- Dec 49° 21°
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 Supply each month?
July is the warmest month, with normal highs of 94°F; January the coldest, with normal lows of 20°F. The most precipitation falls in June (3.77 in), the least in February (0.76 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 48°F | 20°F | 33.6°F | 0.92 | 2.7 | 4 | <1 | 29 | 10 h |
| February | 52°F | 23°F | 37.4°F | 0.76 | 1.9 | 4 | <1 | 23 | 10 h 50 min |
| March | 62°F | 32°F | 46.5°F | 1.92 | 3.5 | 6 | <1 | 15 | 11 h 50 min |
| April | 71°F | 41°F | 55.8°F | 2.19 | 0.1 | 7 | 2 | 6 | 13 h 10 min |
| May | 79°F | 52°F | 65.9°F | 3.19 | 0.0 | 8 | 5 | 1 | 14 h 10 min |
| June | 88°F | 63°F | 75.7°F | 3.77 | 0.0 | 7 | 14 | <1 | 14 h 40 min |
| July | 94°F | 68°F | 80.8°F | 2.63 | 0.0 | 6 | 24 | <1 | 14 h 30 min |
| August | 93°F | 65°F | 78.9°F | 3.07 | 0.0 | 7 | 22 | <1 | 13 h 40 min |
| September | 85°F | 56°F | 70.3°F | 1.99 | 0.0 | 5 | 9 | <1 | 12 h 30 min |
| October | 73°F | 43°F | 57.7°F | 2.49 | 0.1 | 6 | 1 | 5 | 11 h 20 min |
| November | 60°F | 30°F | 45.0°F | 1.05 | 0.4 | 4 | <1 | 18 | 10 h 20 min |
| December | 49°F | 21°F | 35.0°F | 1.24 | 3.7 | 4 | <1 | 28 | 9 h 40 min |
| Year (annual) | 71°F | 43°F | 56.9°F | 25.22 | 12.4 | 69 | 77 | 124 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 9°C | −7°C | 0.9°C | 23 mm | 7 cm |
| February | 11°C | −5°C | 3.0°C | 19 mm | 5 cm |
| March | 16°C | 0°C | 8.1°C | 49 mm | 9 cm |
| April | 22°C | 5°C | 13.2°C | 56 mm | 0 cm |
| May | 26°C | 11°C | 18.8°C | 81 mm | 0 cm |
| June | 31°C | 17°C | 24.3°C | 96 mm | 0 cm |
| July | 34°C | 20°C | 27.1°C | 67 mm | 0 cm |
| August | 34°C | 18°C | 26.1°C | 78 mm | 0 cm |
| September | 29°C | 13°C | 21.3°C | 51 mm | 0 cm |
| October | 23°C | 6°C | 14.3°C | 63 mm | 0 cm |
| November | 15°C | −1°C | 7.2°C | 27 mm | 1 cm |
| December | 9°C | −6°C | 1.7°C | 31 mm | 9 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00343304; 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 Supply?
Normal highs sit between 65°F and 85°F in April, May, September and October. Of those, September has the fewest days with rain (5).
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 USC00343304.
When is the last frost in Fort Supply?
In Fort Supply, the last spring frost (32°F) comes after April 21 in half of years and after May 5 in one year in ten; the first autumn frost comes before October 19 in half of years and before October 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
- April 211 year in 10 after May 5; 9 in 10 after April 8
- First autumn frost, half of years before
- October 191 year in 10 before October 4; 9 in 10 before October 31
NOAA puts the median frost-free season at 179 days, and the season without a hard freeze (28°F) at 200 days.
A hard freeze (28°F) comes after April 11 in half of springs and before October 28 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fort Supply in zone 7a in ZIP code 73841, the nearest ZIP area.
Frost dates for every NOAA station in Oklahoma · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00343304; 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 Fort Supply?
In a normal year in Fort Supply, 77 days a year reach 90°F (18 of them 100°F or more), 124 nights fall to 32°F or colder and 69 days bring measurable precipitation.
- Days at 90°F or more
- 77a normal year
- Days at 100°F or more
- 18a normal year
- Nights at 32°F or colder
- 124a normal year
- Days that stay below freezing
- 14high of 32°F or less
- Days with 0.01 inch of precipitation
- 69a normal year
- Days with 1 inch of snow or more
- 4a normal year
The highest temperature in this station's record (since 1940) is 110°F, on June 15, 1953; the lowest is −18°F, on January 4, 1947.
The wettest calendar year on that record is 1957, with 40.63 in; the snowiest season is 1987–88, with 40.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00343304; records: ACIS (NOAA Regional Climate Centers), station USC00343304. Records use complete months only; a month missing more than three days is left out.
How sunny is Fort Supply?
Over a year 83% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fort Supply, 4.9 kWh per square metre a day. July is the sunniest month (88%) and February the cloudiest (76%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 80% | 2.8 |
| February | 76% | 3.6 |
| March | 79% | 4.8 |
| April | 80% | 5.9 |
| May | 81% | 6.6 |
| June | 87% | 7.3 |
| July | 88% | 7.1 |
| August | 87% | 6.3 |
| September | 86% | 5.3 |
| October | 82% | 4.0 |
| November | 82% | 3.1 |
| December | 79% | 2.5 |
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 Supply need?
A normal year in Fort Supply brings 4,555 heating degree days, 15% fewer than the median U.S. place (5,373), and 1,638 cooling degree days, 80% 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 4,414 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 972 | 0 |
| February | 773 | 0 |
| March | 576 | 4 |
| April | 298 | 23 |
| May | 93 | 119 |
| June | 8 | 328 |
| July | 1 | 490 |
| August | 2 | 433 |
| September | 43 | 203 |
| October | 259 | 34 |
| November | 602 | 2 |
| December | 930 | 0 |
| Year (annual) | 4,555 | 1,638 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00343304. 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 Supply's climate compare?
Fort Supply is warmer than 5 of the other 133 places with their own NOAA record in Oklahoma, and wetter than 7. Across the 7,247 U.S. stations with normals, its annual mean of 56.9°F is warmer than 66%.
In the Köppen classification computed from these normals, Fort Supply is Cfa: temperate, no dry season, hot 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.
Which places near Fort Supply share this climate record?
May has no NOAA station with 1991-2020 normals of its 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.
- May, OK30 people · 13 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 Fort Supply's climate
What is the coldest month in Fort Supply?
January, with a normal high of 48°F and a normal low of 20°F. The warmest is July (94°F by day, 68°F at night).
Does it snow in Fort Supply?
Yes: 12 inches in a normal year, falling on 7 days with 0.1 inch or more, the most in December (3.7 inches).
What is the rainiest month in Fort Supply?
June, with 3.77 in of precipitation in a normal year; the driest is February with 0.76 in.
What plant hardiness zone is Fort Supply in?
The USDA's 2023 map puts Fort Supply in zone 7a in ZIP code 73841, the nearest ZIP area.
How late can frost come in Fort Supply?
In half of years the last 32°F night comes after April 21; in one year in ten it comes after May 5. Waiting until May 5 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Oklahoma climateThe statewide normals and every place in the state
- Woodward, OK11 miles from this station, 59.2°F a year
- Buffalo, OK21 miles from this station, 58.8°F a year
- Gage, OK22 miles from this station, 59.1°F a year
- Freedom, OK28 miles from this station, 57.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made