Hammon, Oklahoma climate: Normal weather by month, frost dates and records
Hammon's normal year runs from 22°F January nights to 94°F July afternoons, with 27.6 inches of precipitation and 7 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 14.8°C, January lows of −5°C, July highs of 35°C, 701 mm of precipitation a year.
- NOAA stationHammon (3 mi SSW)
- Station IDUSC00343871
- Location35.59°N 99.40°W
- Elevation1,820 ft (555 m)
- Population463
On October 23, the normal high in Hammon is 71°F and the normal low 42°F, and the chance of measurable rain or snow is 13%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Hammon.
- Jan 50° 22°
- Feb 55° 25°
- Mar 64° 34°
- Apr 73° 43°
- May 81° 54°
- Jun 89° 64°
- Jul 94° 69°
- Aug 94° 67°
- Sep 85° 58°
- Oct 74° 45°
- Nov 62° 32°
- Dec 51° 23°
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 Hammon each month?
July is the warmest month, with normal highs of 94°F; January the coldest, with normal lows of 22°F. The most precipitation falls in May (3.89 in), the least in February (0.82 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 50°F | 22°F | 36.3°F | 0.92 | 1.8 | 3 | <1 | 28 | 10 h |
| February | 55°F | 25°F | 40.1°F | 0.82 | 1.2 | 2 | <1 | 21 | 10 h 50 min |
| March | 64°F | 34°F | 48.9°F | 2.03 | 1.8 | 4 | <1 | 15 | 11 h 50 min |
| April | 73°F | 43°F | 57.6°F | 2.62 | 0.0 | 4 | 1 | 5 | 13 h |
| May | 81°F | 54°F | 67.1°F | 3.89 | 0.0 | 6 | 5 | <1 | 14 h |
| June | 89°F | 64°F | 76.8°F | 3.49 | 0.0 | 7 | 12 | <1 | 14 h 30 min |
| July | 94°F | 69°F | 81.4°F | 2.23 | 0.0 | 4 | 24 | <1 | 14 h 20 min |
| August | 94°F | 67°F | 80.2°F | 2.94 | 0.0 | 5 | 23 | <1 | 13 h 30 min |
| September | 85°F | 58°F | 71.4°F | 2.94 | 0.0 | 5 | 9 | <1 | 12 h 30 min |
| October | 74°F | 45°F | 59.4°F | 2.65 | 0.0 | 4 | 1 | 4 | 11 h 20 min |
| November | 62°F | 32°F | 46.8°F | 1.53 | 0.0 | 3 | <1 | 16 | 10 h 20 min |
| December | 51°F | 23°F | 37.2°F | 1.54 | 2.3 | 3 | <1 | 27 | 9 h 50 min |
| Year (annual) | 73°F | 45°F | 58.6°F | 27.60 | 7.1 | 51 | 74 | 116 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 10°C | −5°C | 2.4°C | 23 mm | 5 cm |
| February | 13°C | −4°C | 4.5°C | 21 mm | 3 cm |
| March | 18°C | 1°C | 9.4°C | 52 mm | 5 cm |
| April | 23°C | 6°C | 14.2°C | 67 mm | 0 cm |
| May | 27°C | 12°C | 19.5°C | 99 mm | 0 cm |
| June | 32°C | 18°C | 24.9°C | 89 mm | 0 cm |
| July | 35°C | 20°C | 27.4°C | 57 mm | 0 cm |
| August | 34°C | 19°C | 26.8°C | 75 mm | 0 cm |
| September | 30°C | 14°C | 21.9°C | 75 mm | 0 cm |
| October | 23°C | 7°C | 15.2°C | 67 mm | 0 cm |
| November | 16°C | 0°C | 8.2°C | 39 mm | 0 cm |
| December | 11°C | −5°C | 2.9°C | 39 mm | 6 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00343871; 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 Hammon?
Normal highs sit between 65°F and 85°F in April, May and October. Of those, October has the fewest days with rain (4).
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 USC00343871.
When is the last frost in Hammon?
In Hammon, the last spring frost (32°F) comes after April 16 in half of years and after May 2 in one year in ten; the first autumn frost comes before October 23 in half of years and before October 6 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 161 year in 10 after May 2; 9 in 10 after March 31
- First autumn frost, half of years before
- October 231 year in 10 before October 6; 9 in 10 before November 4
NOAA puts the median frost-free season at 191 days, and the season without a hard freeze (28°F) at 211 days.
A hard freeze (28°F) comes after April 4 in half of springs and before October 31 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Hammon in zone 7a in ZIP code 73650, 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 USC00343871; 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 Hammon?
In a normal year in Hammon, 74 days a year reach 90°F (12 of them 100°F or more), 116 nights fall to 32°F or colder and 51 days bring measurable precipitation.
- Days at 90°F or more
- 74a normal year
- Days at 100°F or more
- 12a normal year
- Nights at 32°F or colder
- 116a normal year
- Days that stay below freezing
- 11high of 32°F or less
- Days with 0.01 inch of precipitation
- 51a normal year
- Days with 1 inch of snow or more
- 3a normal year
The highest temperature in this station's record (since 1920) is 115°F, on June 26, 1980; the lowest is −18°F, on January 4, 1947.
The wettest calendar year on that record is 1923, with 46.00 in; the snowiest season is 1972–73, with 38.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00343871; records: ACIS (NOAA Regional Climate Centers), station USC00343871. Records use complete months only; a month missing more than three days is left out.
How sunny is Hammon?
Over a year 83% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Hammon, 5.0 kWh per square metre a day. July is the sunniest month (88%) and February the cloudiest (77%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 82% | 3.0 |
| February | 77% | 3.7 |
| March | 79% | 4.9 |
| April | 80% | 6.0 |
| May | 80% | 6.5 |
| June | 87% | 7.3 |
| July | 88% | 7.1 |
| August | 87% | 6.4 |
| September | 86% | 5.3 |
| October | 82% | 4.1 |
| November | 82% | 3.2 |
| December | 79% | 2.6 |
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 Hammon need?
A normal year in Hammon brings 4,086 heating degree days, 24% fewer than the median U.S. place (5,373), and 1,777 cooling degree days, 96% 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 4,685 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 891 | 0 |
| February | 697 | 0 |
| March | 507 | 6 |
| April | 249 | 29 |
| May | 73 | 137 |
| June | 3 | 355 |
| July | 0 | 507 |
| August | 1 | 470 |
| September | 35 | 227 |
| October | 215 | 42 |
| November | 552 | 4 |
| December | 863 | 0 |
| Year (annual) | 4,086 | 1,777 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00343871. 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 Hammon's climate compare?
Hammon is warmer than 18 of the other 133 places with their own NOAA record in Oklahoma, and wetter than 15. Across the 7,247 U.S. stations with normals, its annual mean of 58.6°F is warmer than 71%.
In the Köppen classification computed from these normals, Hammon 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.
Questions about Hammon's climate
What is the coldest month in Hammon?
January, with a normal high of 50°F and a normal low of 22°F. The warmest is July (94°F by day, 69°F at night).
Does it snow in Hammon?
Yes: 7 inches in a normal year, falling on 3 days with 0.1 inch or more, the most in December (2.3 inches).
What is the rainiest month in Hammon?
May, with 3.89 in of precipitation in a normal year; the driest is February with 0.82 in.
What plant hardiness zone is Hammon in?
The USDA's 2023 map puts Hammon in zone 7a in ZIP code 73650, the nearest ZIP area.
How late can frost come in Hammon?
In half of years the last 32°F night comes after April 16; in one year in ten it comes after May 2. Waiting until May 2 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Oklahoma climateThe statewide normals and every place in the state
- Butler, OK7 miles from this station, 59.8°F a year
- Elk City, OK15 miles from this station, 60.1°F a year
- Cheyenne, OK19 miles from this station, 59.8°F a year
- Bessie, OK23 miles from this station, 60.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made