Marietta, Ohio climate: Normal weather by month, frost dates and records
Marietta's normal year runs from 23°F January nights to 85°F July afternoons, with 45.3 inches of precipitation and 16 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.1°C, January lows of −5°C, July highs of 30°C, 1,150 mm of precipitation a year.
- NOAA stationMarietta Wastewater Treatment Plant
- Station IDUSC00334927
- Location39.41°N 81.43°W
- Elevation610 ft (186 m)
- From the center1 miles
- Population13,039
On October 14, the normal high in Marietta is 67°F and the normal low 45°F, and the chance of measurable rain or snow is 37%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Marietta.
- Jan 40° 23°
- Feb 43° 24°
- Mar 53° 31°
- Apr 66° 41°
- May 75° 52°
- Jun 82° 61°
- Jul 85° 65°
- Aug 85° 63°
- Sep 79° 56°
- Oct 67° 44°
- Nov 54° 34°
- Dec 44° 28°
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 Marietta each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 23°F. The most precipitation falls in June (4.87 in), the least in November (2.91 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 40°F | 23°F | 31.1°F | 3.49 | 7.2 | 15 | <1 | 25 | 9 h 40 min |
| February | 43°F | 24°F | 33.5°F | 3.14 | 4.0 | 13 | <1 | 22 | 10 h 40 min |
| March | 53°F | 31°F | 41.9°F | 3.98 | 2.7 | 14 | <1 | 18 | 11 h 50 min |
| April | 66°F | 41°F | 53.2°F | 3.98 | 0.1 | 14 | <1 | 6 | 13 h 10 min |
| May | 75°F | 52°F | 63.2°F | 4.35 | 0.0 | 14 | 1 | <1 | 14 h 20 min |
| June | 82°F | 61°F | 71.4°F | 4.87 | 0.0 | 13 | 3 | <1 | 15 h |
| July | 85°F | 65°F | 75.3°F | 4.79 | 0.0 | 12 | 7 | <1 | 14 h 40 min |
| August | 85°F | 63°F | 74.0°F | 3.60 | 0.0 | 10 | 6 | <1 | 13 h 50 min |
| September | 79°F | 56°F | 67.4°F | 3.39 | 0.0 | 10 | 2 | <1 | 12 h 30 min |
| October | 67°F | 44°F | 55.2°F | 3.16 | 0.0 | 11 | <1 | 3 | 11 h 10 min |
| November | 54°F | 34°F | 43.9°F | 2.91 | 0.2 | 12 | <1 | 15 | 10 h |
| December | 44°F | 28°F | 35.9°F | 3.61 | 2.1 | 14 | <1 | 22 | 9 h 20 min |
| Year (annual) | 64°F | 44°F | 53.8°F | 45.27 | 16.3 | 152 | 19 | 112 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 4°C | −5°C | −0.5°C | 89 mm | 18 cm |
| February | 6°C | −4°C | 0.8°C | 80 mm | 10 cm |
| March | 12°C | −1°C | 5.5°C | 101 mm | 7 cm |
| April | 19°C | 5°C | 11.8°C | 101 mm | 0 cm |
| May | 24°C | 11°C | 17.3°C | 110 mm | 0 cm |
| June | 28°C | 16°C | 21.9°C | 124 mm | 0 cm |
| July | 30°C | 19°C | 24.1°C | 122 mm | 0 cm |
| August | 29°C | 17°C | 23.3°C | 91 mm | 0 cm |
| September | 26°C | 13°C | 19.7°C | 86 mm | 0 cm |
| October | 19°C | 7°C | 12.9°C | 80 mm | 0 cm |
| November | 12°C | 1°C | 6.6°C | 74 mm | 1 cm |
| December | 7°C | −2°C | 2.2°C | 92 mm | 5 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00334927; 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 Marietta?
Normal highs sit between 65°F and 85°F in April, May, June, August, September and October. Of those, September has the fewest days with rain (10).
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 USC00334927.
When is the last frost in Marietta?
In Marietta, the last spring frost (32°F) comes after April 18 in half of years and after May 4 in one year in ten; the first autumn frost comes before October 27 in half of years and before October 13 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 181 year in 10 after May 4; 9 in 10 after April 5
- First autumn frost, half of years before
- October 271 year in 10 before October 13; 9 in 10 before November 6
NOAA puts the median frost-free season at 191 days, and the season without a hard freeze (28°F) at 214 days.
A hard freeze (28°F) comes after April 5 in half of springs and before November 5 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Marietta in zone 6b in ZIP code 45750, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Marietta's NOAA station is in zone 7a: the coldest night of a typical year reaches 1°F (29 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 Ohio · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00334927; 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 Marietta?
In a normal year in Marietta, 19 days a year reach 90°F, 112 nights fall to 32°F or colder and 152 days bring measurable precipitation.
- Days at 90°F or more
- 19a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 112a normal year
- Days that stay below freezing
- 21high of 32°F or less
- Days with 0.01 inch of precipitation
- 152a normal year
- Days with 1 inch of snow or more
- 6a normal year
The highest temperature in this station's record (since 1963) is 103°F, on July 8, 2012; the lowest is −23°F, on January 19, 1994.
The wettest calendar year on that record is 1989, with 59.15 in; the snowiest season is 1993–94, with 48.9 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00334927; records: ACIS (NOAA Regional Climate Centers), station USC00334927. Records use complete months only; a month missing more than three days is left out.
How sunny is Marietta?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Marietta, 3.9 kWh per square metre a day. August is the sunniest month (79%) and December the cloudiest (56%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 57% | 1.7 |
| February | 59% | 2.5 |
| March | 64% | 3.6 |
| April | 69% | 4.8 |
| May | 71% | 5.5 |
| June | 76% | 6.1 |
| July | 77% | 5.9 |
| August | 79% | 5.4 |
| September | 78% | 4.5 |
| October | 70% | 3.1 |
| November | 68% | 2.2 |
| December | 56% | 1.5 |
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 Marietta need?
A normal year in Marietta brings 5,076 heating degree days, 6% fewer than the median U.S. place (5,373), and 1,038 cooling degree days, 14% 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 3,587 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,051 | 0 |
| February | 881 | 0 |
| March | 719 | 1 |
| April | 364 | 10 |
| May | 132 | 76 |
| June | 16 | 206 |
| July | 1 | 320 |
| August | 2 | 281 |
| September | 55 | 127 |
| October | 320 | 16 |
| November | 633 | 0 |
| December | 904 | 0 |
| Year (annual) | 5,076 | 1,038 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00334927. 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 Marietta been warmer than normal lately?
2025 averaged 54.6°F, 0.9°F above the 1991-2020 normal of 53.8°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 55.8°F | +2.0°F | 43.47 | – |
| 2022 | 54.4°F | +0.6°F | 46.18 | 20.5 |
| 2023 | 55.9°F | +2.1°F | 43.57 | 0.0 |
| 2024 | 57.4°F | +3.6°F | 39.66 | – |
| 2025 | 54.6°F | +0.9°F | 46.59 | – |
Over 52 complete years from 1964 to 2025, the station's annual mean temperature rose at a fitted 4.3°F per century (+0.24°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00334927; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Marietta's climate compare?
Marietta is warmer than 85 of the other 98 places with their own NOAA record in Ohio, and wetter than 84. Across the 7,247 U.S. stations with normals, its annual mean of 53.8°F is warmer than 56%.
In the Köppen classification computed from these normals, Marietta 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 Marietta share this climate record?
11 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.
- Vienna, WV10,406 people · 8 mi SW
- Blennerhassett, WV3,229 people · 15 mi SW
- Williamstown, WV2,951 people · 1 mi SW
- Mineralwells, WV2,489 people · 16 mi S
- Lubeck, WV1,412 people · 16 mi SW
- Boaz, WV1,374 people · 4 mi SW
- Washington, WV1,129 people · 17 mi SW
- North Hills, WV812 people · 8 mi SW
- Newark, WV424 people · 20 mi S
- Waverly, WV395 people · 6 mi SE
- Kanawha, WV130 people · 14 mi S
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 Marietta's climate
What is the coldest month in Marietta?
January, with a normal high of 40°F and a normal low of 23°F. The warmest is July (85°F by day, 65°F at night).
Does it snow in Marietta?
Yes: 16 inches in a normal year, falling on 12 days with 0.1 inch or more, the most in January (7.2 inches).
What is the rainiest month in Marietta?
June, with 4.87 in of precipitation in a normal year; the driest is November with 2.91 in.
What plant hardiness zone is Marietta in?
The USDA's 2023 map puts Marietta in zone 6b in ZIP code 45750, the nearest ZIP area. By the same method at Marietta's NOAA station, the coldest night of a typical year reaches 1°F (29 years, 1991-2020): zone 7a.
How late can frost come in Marietta?
In half of years the last 32°F night comes after April 18; in one year in ten it comes after May 4. Waiting until May 4 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Ohio climateThe statewide normals and every place in the state
- Parkersburg, WV4 miles from this station, 54.2°F a year
- Newport, OH11 miles from this station, 53.1°F a year
- Beverly, OH14 miles from this station, 52.9°F a year
- Caldwell, OH21 miles from this station, 51.5°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made