St. Joseph, MO climate
St. Joseph has chilly winters and warm summers. A typical July afternoon reaches 87°, a January night drops to 18°, and about 21 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in St. Joseph feels like
Winter
Spring
Summer
Fall
St. Joseph 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 | 36° | 18° | 1.0" | 5.5" | 7 | 11 | 20° – 39° |
| February | 42° | 22° | 1.3" | 5.9" | 6 | 8 | 22° – 42° |
| March | 54° | 33° | 2.2" | 2.2" | 9 | 3 | 36° – 58° |
| April | 65° | 42° | 3.7" | 0.8" | 11 | 0 | 46° – 59° |
| May | 75° | 53° | 5.0" | 0.1" | 12 | 0 | 59° – 73° |
| June | 84° | 63° | 4.7" | 0 | 10 | 0 | 69° – 77° |
| July | 87° | 67° | 5.2" | 0 | 9 | 0 | 72° – 83° |
| August | 86° | 65° | 4.0" | 0 | 9 | 0 | 70° – 81° |
| September | 79° | 56° | 3.7" | 0 | 8 | 0 | 62° – 73° |
| October | 67° | 44° | 3.1" | 0.3" | 8 | 0 | 49° – 60° |
| November | 52° | 33° | 2.0" | 1.3" | 6 | 1 | 35° – 51° |
| December | 40° | 23° | 1.5" | 5.0" | 6 | 7 | 17° – 39° |
| Year | 64° | 43° | 37.3" | 21.1" | 101 | 30 |
“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. Joseph
St. Joseph gets 37 inches of rain and melted snow a year. July is the wettest month and January the driest. Rain or snow falls on about 101 days a year. Snow covers the ground about 30 days of the year.
About 180 frost-free days a year
In half of years the last 32° night comes by April 19 and the first one by October 17. That leaves about 180 frost-free days for gardens, longer than 53% of U.S. towns.
Heating and cooling a home in St. Joseph
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In St. Joseph, 81% of that work is heating and 19% 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.
St. Joseph and its neighbors
St. Joseph borders 1 town with climate data. January nights across them vary by 0.4°. Washington has both the coldest January nights (18°) and the hottest July afternoons (88°). St. Joseph’s January low is 18° and its July high 87°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How St. Joseph 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. Joseph averaged 0.7° warmer than the 1900s. The biggest change is in March (+2.1°). The shift is smaller than in 90% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at St. Joseph’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. March swings the most: between 1991 and 2020 its average temperature ranged from 36° to 58°. June is the most reliable, staying within 8°.
Common questions about St. Joseph’s climate
What is the coldest month in St. Joseph?
January, with a typical high of 36° and a low of 18°.
What is the hottest month in St. Joseph?
July, with a typical high of 87° and a low of 67°. About 39 days a year reach 90°.
How much snow does St. Joseph get?
About 21 inches in a normal winter, most of it in February.
When is the first frost in St. Joseph?
In half of years the first 32° night comes by October 17, and the last spring frost by April 19.
What is the rainiest month in St. Joseph?
July, with 5.2 inches of rain and melted snow. The year totals 37 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for St. Joseph itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Troy 3n, KS (15 mi, snow) and St Joseph Rosecrans Airport, MO (6 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.