Hamilton, Missouri climate: Normal weather by month, frost dates and records
Hamilton's normal year runs from 16°F January nights to 87°F July afternoons, with 39.9 inches of precipitation and 8 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.1°C, January lows of −9°C, July highs of 30°C, 1,014 mm of precipitation a year.
- NOAA stationHamilton (2 mi W)
- Station IDUSC00233568
- Location39.74°N 94.03°W
- Elevation900 ft (274 m)
- From the center2 miles
- Population1,741
On October 23, the normal high in Hamilton is 63°F and the normal low 39°F, and the chance of measurable rain or snow is 25%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Hamilton.
- Jan 35° 16°
- Feb 40° 20°
- Mar 52° 30°
- Apr 63° 40°
- May 73° 52°
- Jun 82° 62°
- Jul 87° 66°
- Aug 86° 64°
- Sep 78° 54°
- Oct 66° 42°
- Nov 52° 30°
- Dec 40° 20°
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 Hamilton each month?
July is the warmest month, with normal highs of 87°F; January the coldest, with normal lows of 16°F. The most precipitation falls in May (5.78 in), the least in January (1.10 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 35°F | 16°F | 25.4°F | 1.10 | 2.9 | 6 | <1 | 30 | 9 h 40 min |
| February | 40°F | 20°F | 29.9°F | 1.64 | 1.5 | 6 | <1 | 26 | 10 h 40 min |
| March | 52°F | 30°F | 41.2°F | 2.81 | 1.0 | 8 | <1 | 21 | 11 h 50 min |
| April | 63°F | 40°F | 51.7°F | 3.99 | 0.1 | 10 | <1 | 9 | 13 h 10 min |
| May | 73°F | 52°F | 62.4°F | 5.78 | 0.0 | 11 | 1 | 1 | 14 h 20 min |
| June | 82°F | 62°F | 72.0°F | 4.96 | 0.0 | 10 | 5 | <1 | 15 h |
| July | 87°F | 66°F | 76.4°F | 3.86 | 0.0 | 8 | 12 | <1 | 14 h 40 min |
| August | 86°F | 64°F | 74.6°F | 4.27 | 0.0 | 8 | 9 | <1 | 13 h 50 min |
| September | 78°F | 54°F | 66.0°F | 4.25 | 0.0 | 8 | 3 | 1 | 12 h 30 min |
| October | 66°F | 42°F | 53.9°F | 3.29 | 0.0 | 8 | <1 | 7 | 11 h 10 min |
| November | 52°F | 30°F | 40.9°F | 2.25 | 0.5 | 6 | <1 | 19 | 10 h |
| December | 40°F | 20°F | 30.0°F | 1.72 | 1.6 | 6 | <1 | 29 | 9 h 20 min |
| Year (annual) | 63°F | 41°F | 52.0°F | 39.92 | 7.6 | 95 | 29 | 141 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 2°C | −9°C | −3.7°C | 28 mm | 7 cm |
| February | 5°C | −7°C | −1.2°C | 42 mm | 4 cm |
| March | 11°C | −1°C | 5.1°C | 71 mm | 3 cm |
| April | 17°C | 5°C | 10.9°C | 101 mm | 0 cm |
| May | 23°C | 11°C | 16.9°C | 147 mm | 0 cm |
| June | 28°C | 17°C | 22.2°C | 126 mm | 0 cm |
| July | 30°C | 19°C | 24.7°C | 98 mm | 0 cm |
| August | 30°C | 18°C | 23.7°C | 108 mm | 0 cm |
| September | 26°C | 12°C | 18.9°C | 108 mm | 0 cm |
| October | 19°C | 5°C | 12.2°C | 84 mm | 0 cm |
| November | 11°C | −1°C | 4.9°C | 57 mm | 1 cm |
| December | 4°C | −7°C | −1.1°C | 44 mm | 4 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00233568; 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 Hamilton?
Normal highs sit between 65°F and 85°F in May, June, September and October. 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 USC00233568.
When is the last frost in Hamilton?
In Hamilton, the last spring frost (32°F) comes after April 23 in half of years and after May 6 in one year in ten; the first autumn frost comes before October 17 in half of years and before October 2 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 231 year in 10 after May 6; 9 in 10 after April 9
- First autumn frost, half of years before
- October 171 year in 10 before October 2; 9 in 10 before October 29
NOAA puts the median frost-free season at 175 days, and the season without a hard freeze (28°F) at 196 days.
A hard freeze (28°F) comes after April 13 in half of springs and before October 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Hamilton in zone 6a in ZIP code 64644, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Hamilton's NOAA station is in zone 5b: the coldest night of a typical year reaches −12°F (16 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Missouri · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00233568; 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 Hamilton?
In a normal year in Hamilton, 29 days a year reach 90°F (2 of them 100°F or more), 141 nights fall to 32°F or colder and 95 days bring measurable precipitation.
- Days at 90°F or more
- 29a normal year
- Days at 100°F or more
- 2a normal year
- Nights at 32°F or colder
- 141a normal year
- Days that stay below freezing
- 33high of 32°F or less
- Days with 0.01 inch of precipitation
- 95a normal year
- Days with 1 inch of snow or more
- 3a normal year
The highest temperature in this station's record (since 1954) is 109°F, on July 14, 1954; the lowest is −27°F, on January 15, 1979.
The wettest calendar year on that record is 1998, with 52.96 in; the snowiest season is 1961–62, with 50.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00233568; records: ACIS (NOAA Regional Climate Centers), station USC00233568. Records use complete months only; a month missing more than three days is left out.
How sunny is Hamilton?
Over a year 76% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Hamilton, 4.2 kWh per square metre a day. July is the sunniest month (83%) and March the cloudiest (69%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 69% | 2.1 |
| February | 71% | 3.0 |
| March | 69% | 3.9 |
| April | 71% | 5.0 |
| May | 73% | 5.7 |
| June | 80% | 6.5 |
| July | 83% | 6.5 |
| August | 82% | 5.7 |
| September | 82% | 4.8 |
| October | 75% | 3.4 |
| November | 74% | 2.4 |
| December | 70% | 1.9 |
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 Hamilton need?
A normal year in Hamilton brings 5,790 heating degree days, 8% more than the median U.S. place (5,373), and 1,101 cooling degree days, 21% more 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 3,550 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,227 | 0 |
| February | 983 | 0 |
| March | 741 | 2 |
| April | 408 | 10 |
| May | 152 | 71 |
| June | 15 | 225 |
| July | 2 | 356 |
| August | 5 | 302 |
| September | 86 | 117 |
| October | 362 | 18 |
| November | 724 | 1 |
| December | 1,086 | 0 |
| Year (annual) | 5,790 | 1,101 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00233568. 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 Hamilton been warmer than normal lately?
Over 46 complete years from 1957 to 2017, 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 Hamilton's climate compare?
Hamilton is warmer than 13 of the other 133 places with their own NOAA record in Missouri, and wetter than 21. Across the 7,247 U.S. stations with normals, its annual mean of 52.0°F is warmer than 49%.
In the Köppen classification computed from these normals, Hamilton is Dfa: continental, 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 Hamilton share this climate record?
6 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.
- Braymer, MO753 people · 16 mi SE
- Polo, MO508 people · 13 mi S
- Kingston, MO295 people · 7 mi S
- Kidder, MO272 people · 5 mi NW
- Breckenridge, MO249 people · 12 mi E
- Cowgill, MO172 people · 14 mi SE
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 Hamilton's climate
What is the coldest month in Hamilton?
January, with a normal high of 35°F and a normal low of 16°F. The warmest is July (87°F by day, 66°F at night).
Does it snow in Hamilton?
Yes: 8 inches in a normal year, falling on 4 days with 0.1 inch or more, the most in January (2.9 inches).
What is the rainiest month in Hamilton?
May, with 5.78 in of precipitation in a normal year; the driest is January with 1.10 in.
What plant hardiness zone is Hamilton in?
The USDA's 2023 map puts Hamilton in zone 6a in ZIP code 64644, the nearest ZIP area. By the same method at Hamilton's NOAA station, the coldest night of a typical year reaches −12°F (16 years, 1991-2020): zone 5b.
How late can frost come in Hamilton?
In half of years the last 32°F night comes after April 23; in one year in ten it comes after May 6. Waiting until May 6 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Missouri climateThe statewide normals and every place in the state
- Cameron, MO12 miles from this station, 52.5°F a year
- Gallatin, MO12 miles from this station, 51.6°F a year
- Amity, MO20 miles from this station, 51.6°F a year
- Chillicothe, MO25 miles from this station, 53.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made