St. Mary, KY climate
St. Mary has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 87°, a January night drops to 25°, and about 3 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in St. Mary feels like
Winter
Spring
Summer
Fall
St. Mary 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 | 43° | 25° | 3.8" | 0.8" | 10 | 4 | 27° – 43° |
| February | 48° | 28° | 3.9" | 1.7" | 8 | 3 | 27° – 46° |
| March | 57° | 35° | 4.8" | 0.2" | 11 | 1 | 39° – 58° |
| April | 69° | 44° | 4.8" | 0 | 11 | 0 | 50° – 61° |
| May | 77° | 54° | 5.2" | 0 | 10 | 0 | 59° – 71° |
| June | 84° | 62° | 5.0" | 0 | 10 | 0 | 69° – 78° |
| July | 87° | 66° | 4.9" | 0 | 9 | 0 | 72° – 81° |
| August | 87° | 64° | 3.5" | 0 | 7 | 0 | 71° – 81° |
| September | 81° | 57° | 3.9" | 0 | 7 | 0 | 65° – 75° |
| October | 70° | 45° | 3.7" | 0 | 7 | 0 | 53° – 63° |
| November | 57° | 35° | 3.5" | 0 | 9 | 0 | 40° – 52° |
| December | 47° | 29° | 4.5" | 0.6" | 10 | 2 | 27° – 48° |
| Year | 67° | 45° | 51.5" | 3.3" | 108 | 9 |
“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 St. Mary
St. Mary gets 51 inches of rain and melted snow a year. May is the wettest month and November the driest. Rain or snow falls on about 108 days a year. Snow covers the ground about 9 days of the year.
About 180 frost-free days a year
In half of years the last 32° night comes by April 22 and the first one by October 20. That leaves about 180 frost-free days for gardens, longer than 53% of U.S. towns.
Heating and cooling a home in St. Mary
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In St. Mary, 80% of that work is heating and 20% is cooling.
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.
How St. Mary 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 St. Mary averaged 0.8° warmer than the 1900s. The biggest change is in February (+1.8°). The shift is smaller than in 83% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at St. Mary’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 27° to 48°. June is the most reliable, staying within 9°.
Common questions about St. Mary’s climate
What is the coldest month in St. Mary?
January, with a typical high of 43° and a low of 25°.
What is the hottest month in St. Mary?
July, with a typical high of 87° and a low of 66°. About 35 days a year reach 90°.
How much snow does St. Mary get?
About 3 inches in a normal winter, most of it in February.
When is the first frost in St. Mary?
In half of years the first 32° night comes by October 20, and the last spring frost by April 22.
What is the rainiest month in St. Mary?
May, with 5.2 inches of rain and melted snow. The year totals 51 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for St. Mary itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Springfield 2w, KY (10 mi, snow) and Bradfordsville, KY (12 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.