Trenton, Missouri climate: Normal weather by month, frost dates and records
Trenton's normal year runs from 16°F January nights to 89°F July afternoons, with 40.1 inches of precipitation and 17 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.6°C, January lows of −9°C, July highs of 32°C, 1,018 mm of precipitation a year.
- NOAA stationTrenton
- Station IDUSC00238444
- Location40.08°N 93.61°W
- Elevation837 ft (255 m)
- From the centerunder 1 mile
- Population5,588
On October 23, the normal high in Trenton is 63°F and the normal low 40°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 Trenton.
- Jan 35° 16°
- Feb 40° 20°
- Mar 53° 30°
- Apr 64° 41°
- May 75° 53°
- Jun 85° 63°
- Jul 89° 67°
- Aug 87° 64°
- Sep 79° 55°
- Oct 67° 43°
- Nov 52° 31°
- Dec 40° 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 Trenton each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 16°F. The most precipitation falls in May (6.02 in), the least in January (1.13 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 35°F | 16°F | 25.5°F | 1.13 | 4.7 | 6 | <1 | 29 | 9 h 40 min |
| February | 40°F | 20°F | 30.0°F | 1.70 | 4.7 | 7 | <1 | 25 | 10 h 40 min |
| March | 53°F | 30°F | 41.2°F | 2.60 | 2.9 | 9 | <1 | 19 | 11 h 50 min |
| April | 64°F | 41°F | 52.3°F | 3.90 | 0.3 | 11 | <1 | 6 | 13 h 10 min |
| May | 75°F | 53°F | 63.6°F | 6.02 | 0.0 | 12 | 2 | <1 | 14 h 20 min |
| June | 85°F | 63°F | 73.6°F | 4.76 | 0.0 | 10 | 9 | <1 | 15 h |
| July | 89°F | 67°F | 77.8°F | 4.77 | 0.0 | 8 | 15 | <1 | 14 h 50 min |
| August | 87°F | 64°F | 75.5°F | 4.27 | 0.0 | 9 | 11 | <1 | 13 h 50 min |
| September | 79°F | 55°F | 67.1°F | 3.88 | 0.0 | 7 | 5 | <1 | 12 h 30 min |
| October | 67°F | 43°F | 54.7°F | 3.08 | 0.2 | 8 | <1 | 5 | 11 h 10 min |
| November | 52°F | 31°F | 41.3°F | 2.22 | 0.9 | 6 | <1 | 16 | 10 h |
| December | 40°F | 21°F | 30.4°F | 1.74 | 3.5 | 6 | <1 | 27 | 9 h 20 min |
| Year (annual) | 64°F | 42°F | 52.8°F | 40.07 | 17.2 | 100 | 41 | 127 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 2°C | −9°C | −3.6°C | 29 mm | 12 cm |
| February | 5°C | −7°C | −1.1°C | 43 mm | 12 cm |
| March | 11°C | −1°C | 5.1°C | 66 mm | 7 cm |
| April | 18°C | 5°C | 11.3°C | 99 mm | 1 cm |
| May | 24°C | 12°C | 17.6°C | 153 mm | 0 cm |
| June | 29°C | 17°C | 23.1°C | 121 mm | 0 cm |
| July | 32°C | 19°C | 25.4°C | 121 mm | 0 cm |
| August | 31°C | 18°C | 24.2°C | 108 mm | 0 cm |
| September | 26°C | 13°C | 19.5°C | 99 mm | 0 cm |
| October | 19°C | 6°C | 12.6°C | 78 mm | 1 cm |
| November | 11°C | −1°C | 5.2°C | 56 mm | 2 cm |
| December | 4°C | −6°C | −0.9°C | 44 mm | 9 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00238444; 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 Trenton?
Normal highs sit between 65°F and 85°F in May, June, September and October. Of those, September has the fewest days with rain (7).
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 USC00238444.
When is the last frost in Trenton?
In Trenton, the last spring frost (32°F) comes after April 16 in half of years and after April 29 in one year in ten; the first autumn frost comes before October 20 in half of years and before October 5 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 April 29; 9 in 10 after April 3
- First autumn frost, half of years before
- October 201 year in 10 before October 5; 9 in 10 before November 1
NOAA puts the median frost-free season at 184 days, and the season without a hard freeze (28°F) at 204 days.
A hard freeze (28°F) comes after April 6 in half of springs and before October 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Trenton in zone 6a in ZIP code 64683, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Trenton's NOAA station is in zone 6a: the coldest night of a typical year reaches −8°F (20 complete years).
Frost dates for every NOAA station in Missouri · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00238444; 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 Trenton?
In a normal year in Trenton, 41 days a year reach 90°F (4 of them 100°F or more), 127 nights fall to 32°F or colder and 100 days bring measurable precipitation.
- Days at 90°F or more
- 41a normal year
- Days at 100°F or more
- 4a normal year
- Nights at 32°F or colder
- 127a normal year
- Days that stay below freezing
- 34high of 32°F or less
- Days with 0.01 inch of precipitation
- 100a normal year
- Days with 1 inch of snow or more
- 7a normal year
The highest temperature in this station's record (since 1895) is 114°F, on July 15, 1936; the lowest is −26°F, on January 22, 1930.
The wettest calendar year on that record is 1982, with 54.41 in; the snowiest season is 1978–79, with 51.2 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00238444; records: ACIS (NOAA Regional Climate Centers), station USC00238444. Records use complete months only; a month missing more than three days is left out.
How sunny is Trenton?
Over a year 75% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Trenton, 4.1 kWh per square metre a day. July is the sunniest month (82%) and January the cloudiest (66%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 66% | 2.0 |
| February | 70% | 2.9 |
| March | 68% | 3.8 |
| April | 70% | 4.9 |
| May | 72% | 5.7 |
| June | 78% | 6.4 |
| July | 82% | 6.4 |
| August | 80% | 5.6 |
| September | 81% | 4.7 |
| October | 74% | 3.2 |
| November | 72% | 2.3 |
| December | 68% | 1.8 |
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 Trenton need?
A normal year in Trenton brings 5,679 heating degree days, 6% more than the median U.S. place (5,373), and 1,258 cooling degree days, 39% 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 3,765 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,223 | 0 |
| February | 979 | 0 |
| March | 740 | 2 |
| April | 393 | 11 |
| May | 132 | 90 |
| June | 11 | 269 |
| July | 1 | 399 |
| August | 3 | 329 |
| September | 73 | 136 |
| October | 343 | 22 |
| November | 710 | 1 |
| December | 1,071 | 0 |
| Year (annual) | 5,679 | 1,258 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00238444. 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 Trenton been warmer than normal lately?
2025 averaged 53.4°F, 0.6°F above the 1991-2020 normal of 52.8°F. 4 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 53.8°F | +1.0°F | 39.86 | 23.7 |
| 2022 | 51.4°F | −1.4°F | 36.05 | 21.5 |
| 2023 | 54.3°F | +1.5°F | 29.34 | 9.6 |
| 2024 | 55.1°F | +2.3°F | 34.46 | 12.5 |
| 2025 | 53.4°F | +0.6°F | 35.20 | – |
Over 90 complete years from 1900 to 2025, the station's annual mean temperature rose at a fitted 2.5°F per century (+0.14°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00238444; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Trenton's climate compare?
Trenton is warmer than 22 of the other 133 places with their own NOAA record in Missouri, and wetter than 24. Across the 7,247 U.S. stations with normals, its annual mean of 52.8°F is warmer than 53%.
In the Köppen classification computed from these normals, Trenton 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 Trenton share this climate record?
7 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.
- Galt, MO166 people · 12 mi E
- Leisure Lake, MO158 people · 6 mi W
- Laredo, MO155 people · 9 mi SE
- Humphreys, MO88 people · 15 mi E
- Edinburg, MO71 people · 4 mi W
- Tindall, MO49 people · 5 mi N
- Osgood, MO22 people · 16 mi NE
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 Trenton's climate
What is the coldest month in Trenton?
January, with a normal high of 35°F and a normal low of 16°F. The warmest is July (89°F by day, 67°F at night).
Does it snow in Trenton?
Yes: 17 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in January (4.7 inches).
What is the rainiest month in Trenton?
May, with 6.02 in of precipitation in a normal year; the driest is January with 1.13 in.
What plant hardiness zone is Trenton in?
The USDA's 2023 map puts Trenton in zone 6a in ZIP code 64683, the nearest ZIP area. By the same method at Trenton's NOAA station, the coldest night of a typical year reaches −8°F (20 years, 1991-2020): zone 6a.
How late can frost come in Trenton?
In half of years the last 32°F night comes after April 16; in one year in ten it comes after April 29. Waiting until April 29 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Missouri climateThe statewide normals and every place in the state
- Spickard, MO12 miles from this station, 51.4°F a year
- Chillicothe, MO18 miles from this station, 53.8°F a year
- Princeton, MO22 miles from this station, 51.1°F a year
- Gallatin, MO22 miles from this station, 51.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made