Marietta, IN climate
Marietta has chilly winters and warm summers. A typical July afternoon reaches 85°, a January night drops to 21°, and about 15 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Marietta feels like
Winter
Spring
Summer
Fall
Marietta weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 37° | 21° | 3.1" | 5.3" | 11 | 5 | 21° – 40° |
| February | 42° | 24° | 2.6" | 3.8" | 9 | 5 | 20° – 43° |
| March | 52° | 32° | 3.5" | 1.8" | 11 | 1 | 35° – 56° |
| April | 65° | 42° | 4.7" | 0 | 12 | 0 | 47° – 59° |
| May | 74° | 53° | 4.9" | 0 | 12 | 0 | 57° – 71° |
| June | 82° | 61° | 4.8" | 0 | 11 | 0 | 67° – 75° |
| July | 85° | 64° | 4.2" | 0 | 10 | 0 | 69° – 81° |
| August | 84° | 62° | 3.4" | 0 | 8 | 0 | 68° – 78° |
| September | 79° | 55° | 3.2" | 0 | 8 | 0 | 62° – 72° |
| October | 67° | 44° | 3.3" | 0 | 8 | 0 | 51° – 61° |
| November | 53° | 34° | 3.5" | 0.1" | 9 | 0 | 36° – 49° |
| December | 41° | 26° | 3.3" | 3.6" | 11 | 3 | 21° – 43° |
| Year | 63° | 43° | 44.4" | 14.6" | 119 | 15 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Marietta
Marietta gets 44 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 119 days a year. Snow covers the ground about 15 days of the year.
About 187 frost-free days a year
In half of years the last 32° night comes by April 17 and the first one by October 22. That leaves about 187 frost-free days for gardens, longer than 60% of U.S. towns.
Heating and cooling a home in Marietta
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Marietta, 85% of that work is heating and 15% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Marietta and its neighbors
Marietta borders 2 towns with climate data. January nights across them vary by 0.1°. Hendricks has both the coldest January nights (21°) and the hottest July afternoons (85°). Marietta’s January low is 21° and its July high 85°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Marietta compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Marietta averaged 0.8° warmer than the 1900s. The biggest change is in February (+2.2°). The shift is smaller than in 81% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Marietta’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 21° to 43°. June is the most reliable, staying within 8°.
Common questions about Marietta’s climate
What is the coldest month in Marietta?
January, with a typical high of 37° and a low of 21°.
What is the hottest month in Marietta?
July, with a typical high of 85° and a low of 64°. About 18 days a year reach 90°.
How much snow does Marietta get?
About 15 inches in a normal winter, most of it in January.
When is the first frost in Marietta?
In half of years the first 32° night comes by October 22, and the last spring frost by April 17.
What is the rainiest month in Marietta?
May, with 4.9 inches of rain and melted snow. The year totals 44 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Marietta itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Shelbyville Sewage Plt, IN (8 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.