Photo: Eich2004 · CC BY-SA 4.0No extremes in St. Ann: its weather tracks the middle of U.S. towns
The warmest part of a July day comes in at 88° on average. Summer afternoons here are warmer than in 67% of U.S. towns. The latest 30-year average runs 1.0° warmer than 1901–2000’s, with December up the most. Homes need heating from November to March, the months averaging under 50°.
A year in St. Ann at a glance
Each month’s typical high and low, and what it brings.
What stands out about St. Ann’s climate
Compared with towns across the U.S., with St. Ann’s place in Missouri beside it.
What a year in St. Ann feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 215 frost-free days a year
In half of years the last 32° night comes by April 2 and the first by November 4. Frost and day counts come from NOAA’s station at St Louis Lambert International Airport, 1.9 miles from the town’s center, at about the same height.
The 2023 USDA map puts St. Ann’s center in zone 7a: the coldest night of a typical winter, averaged over 1991–2020, reaches about 2°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 17 inches of snow a winter
Snow, measured at St Louis Lambert International Airport, falls mostly in January. Precipitation (rain plus melted snow) adds up to 43 inches a year; May is the wettest month and February the driest. Rain or snow falls on about 114 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in St. Ann
72% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at St Louis Lambert International Airport.
Living with St. Ann’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
215 frost-free days in zone 7a. The last frost comes by Apr 2 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Nov 4.
Months with highs of 62–84° and lows of 40° or more: April, May, September and October. 2.0 miles of trails are waiting.
Parks & trails →Heat waves are 44% of the yearly building losses FEMA expects in St. Ann from natural hazards, the largest share. Normals are averages; the hazards page covers the extremes.
Natural hazards →St. Ann and its neighbors
Every town next door is within a degree of St. Ann in January and July, closer than the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like St. Ann’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| St. Ann, MO | 23° | 88° | 43" | 17" |
| Louisburg, KS | 21° | 88° | 41" | 14" |
| Culpeper, VA | 25° | 88° | 45" | 16" |
| Reading, OH | 23° | 87° | 44" | 16" |
| Chillum, MD | 26° | 88° | 45" | 16" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in St. Ann averaged 1.0° warmer than the 1900s. The biggest change is in December (+2.1°).
A smaller shift than in 81% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How St. Ann compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with St. Ann’s place among Missouri’s.
St. Ann weather by month
Highs, lows and precipitation from NOAA’s grid at St. Ann’s center; snow, wet days and snow on the ground from St Louis Lambert International Airport. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 40° | 23° | 2.5" | 5.7" | 9 | 7 | 25° – 42° |
| February | 45° | 27° | 2.2" | 4.3" | 9 | 4 | 26° – 46° |
| March | 55° | 36° | 3.5" | 2.3" | 11 | 1 | 38° – 59° |
| April | 67° | 45° | 4.8" | 0.2" | 12 | 0 | 49° – 62° |
| May | 76° | 56° | 5.0" | 0.0" | 13 | 0 | 61° – 74° |
| June | 85° | 65° | 4.5" | 0.0" | 10 | 0 | 70° – 79° |
| July | 88° | 69° | 3.9" | 0.0" | 9 | 0 | 74° – 85° |
| August | 87° | 67° | 3.6" | 0.0" | 8 | 0 | 71° – 83° |
| September | 80° | 59° | 3.3" | 0.0" | 7 | 0 | 65° – 76° |
| October | 69° | 47° | 3.2" | 0.0" | 9 | 0 | 52° – 64° |
| November | 55° | 37° | 3.4" | 0.9" | 9 | 1 | 38° – 53° |
| December | 44° | 28° | 2.6" | 3.2" | 9 | 4 | 22° – 44° |
| Year | 66° | 46° | 42.5" | 16.6" | 114 | 17 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 22° to 44°. June is the most reliable, staying within 10°.
Where St. Ann’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at St. Ann’s center.
- Snow: St Louis Lambert International Airport (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: St Louis Lambert International Airport, 1.9 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about St. Ann’s climate
What is the weather like in St. Ann?
A typical July afternoon reaches 88°, a January night drops to 23°, and about 17 inches of snow falls in a normal winter. Milder January nights than 56% of U.S. towns; hotter July afternoons than 67% of U.S. towns.
How cold does it get in St. Ann in winter?
January nights average 23°. About 85 nights a year reach 32° or below and 1 reach 0° or below. In the coldest January of the last 30 years the month averaged 25°.
How much snow does St. Ann get?
About 17 inches in a normal winter at St Louis Lambert International Airport, most of it in January, with snow on the ground about 17 days a year.
How hot does it get in St. Ann?
July, with a typical high of 88° and a low of 69°. About 47 days a year reach 90° and 3 reach 100° (St Louis Lambert International Airport).
When is the first and last frost in St. Ann?
In half of years the last spring frost (32°) comes by April 2 and the first fall frost by November 4, about 215 frost-free days, at St Louis Lambert International Airport.
What growing zone is St. Ann in?
Zone 7a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 2°.
What is the best time of year to visit St. Ann?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is St. Ann getting warmer?
Yes: 1991–2020 averaged 1.0° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 81% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in St. Ann.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.