St. Louis averages 16.5 inches of snow a season, and nearly all of it falls in a five-month stretch between November and March, according to NOAA's 1991-2020 U.S. Climate Normals for St. Louis Lambert International Airport. January is the peak month at 5.7 inches; June through September average zero. Metro East Illinois sits in the same NWS St. Louis forecast area and tracks the identical monthly curve.
- St. Louis averages 16.5 inches of snow a season, with January the peak month at 5.7 inches per NOAA's 1991-2020 normals.
- June through September carry zero average snowfall; the real season runs November through April.
- December (3.5 in) and January (5.7 in) together account for more than half the annual total.
- Metro East Illinois falls in the same NWS St. Louis reporting region and follows the same monthly pattern.
Why this matters
A property manager pricing a St. Louis Snow Removal contract for 2026 needs to know which months carry the risk, not just the season total. A flat "16.5 inches a year" number hides the fact that January and December alone account for more than half of it.
Contract type should follow the calendar. A Zero-Tolerance agreement earns its cost in December and January, when trigger-depth dispatch removes the ambiguity of a call-in service. A Per-Occurrence agreement is defensible in November and April, when the monthly average sits under a inch and most events genuinely are one-offs.
Average snowfall in St. Louis by month
The short answer: St. Louis gets 16.5 inches of snow in an average year, ranging from 5.7 inches in January down to 0.0 inches across four straight summer months. The table below breaks out every month using the same 30-year federal dataset.
| Month | Average Snowfall | Share of Annual Total |
|---|---|---|
| January | 5.7 in | 35% |
| February | 4.4 in | 27% |
| March | 2.0 in | 12% |
| April | 0.2 in | 1% |
| May | 0.0 in | 0% |
| June | 0.0 in | 0% |
| July | 0.0 in | 0% |
| August | 0.0 in | 0% |
| September | 0.0 in | 0% |
| October | 0.1 in | 1% |
| November | 0.6 in | 4% |
| December | 3.5 in | 21% |
| Full Year (All Months) | 16.5 in | 100% |
January leads every month by a wide margin at 5.7 inches, more than a third of the year's total on its own. February trails close behind at 4.4 inches. On the other end, June, July, August, and September average zero measurable snowfall combined — four months that contribute nothing to the season total in the Lambert Airport record.
December and January together account for 9.2 inches, or 56% of the annual average. That two-month stretch is where a contract's trigger depth and response time matter the most, and where a Zero-Tolerance or Seasonal model earns its keep over Per-Occurrence billing.
Methodology and limitations
These figures come from NOAA's 1991-2020 U.S. Climate Normals for St. Louis Lambert International Airport, the official first-order reporting station for the metro. The 30-year average smooths out year-to-year swings — a single season can beat or miss these numbers by several inches in either direction depending on that winter's weather pattern.
One limitation worth naming directly: the dataset reflects airport-site totals. Metro East Illinois and outlying St. Louis County suburbs share the same regional system but can post different totals from an individual storm even in the same week, since snow bands often set up in narrow lines across the metro.
Metro East Illinois vs. St. Louis city and county
Metro East Illinois — Belleville, O'Fallon, Edwardsville, Collinsville — falls inside the same NWS St. Louis forecast area as the city and St. Louis County. There's no separate long-term climate station splitting out a materially different monthly curve for that side of the river; property managers there should plan against the same 16.5-inch annual baseline and the same January-February peak used on the Missouri side.
That doesn't mean every storm hits both sides evenly. Snow bands can drop 2 inches in Belleville and 4 in Chesterfield on the same night. Documented, geo-stamped clock-ins matter here specifically because "it snowed in St. Louis" isn't proof a specific Metro East lot got serviced.
How to use these benchmarks
- Match contract type to the calendar, not the annual average. December and January carry 56% of the season's snow — that's where Zero-Tolerance dispatch (crews move at a set trigger depth, no call needed) removes the ambiguity of waiting on a phone call.
- Treat November and April as shoulder months. Averages under an inch make Per-Occurrence billing defensible there; paying for standby coverage in those months is often money left on the table.
- Build variance into seasonal budgets, not just the flat number. 16.5 inches is a 30-year average — a season 20-30% above or below that is normal, not an anomaly, in a single-year sample.
- Cross-reference trigger depths against the peak months. Review the weather forecast to pre-treatment salting workflow when setting dispatch thresholds for December and January specifically, since those two months set the pace for the whole season's service level.
“A trigger depth means nothing if the crew is watching a monthly average instead of the storm sitting on the lot right now.”
Lock in your snow route before the 2026 season
Documented plowing and salting across St. Louis and Metro East, priced against the actual monthly risk.
FAQ
What is the average snowfall in St. Louis by month?
St. Louis averages 5.7 inches in January, 4.4 in February, 3.5 in December, 2.0 in March, and 0.0 inches from June through September, based on NOAA's 1991-2020 climate normals for Lambert International Airport. The full-year average is 16.5 inches.
Which month gets the most snow in St. Louis?
January is the snowiest month in St. Louis, averaging 5.7 inches, more than a third of the entire year's total. February is second at 4.4 inches.
When does snow season start and end in St. Louis?
Measurable average snowfall runs from November through April, with the real volume concentrated in December through February. October and November average under an inch combined, marking the season's slow start.
Does Metro East Illinois get more snow than St. Louis city?
Metro East Illinois sits in the same NWS St. Louis forecast region and follows the same monthly pattern as the city and county. Individual storms can vary by a few inches from one side of the river to the other, but there's no long-term climate record showing a consistently heavier season on either side.
How much snow does St. Louis get in a typical winter?
A typical St. Louis winter brings 16.5 inches of snow, per NOAA's 30-year climate normals for Lambert International Airport. That figure is an average, not a forecast — individual seasons regularly land 20-30% above or below it.
Will the 2026 winter match the average snowfall numbers?
There's no way to know in advance — the 16.5-inch figure is a historical baseline built from 1991-2020 data, not a prediction for the 2025-2026 or 2026-2027 season. Actual totals depend entirely on that winter's weather pattern.
What snow depth triggers a plow dispatch in St. Louis?
Trigger depths vary by contract, but commercial agreements commonly set dispatch at 1 to 3 inches of accumulation. Check the specific depth written into your service agreement rather than assuming a citywide standard.
Does snow removal cost more in January and February than other months?
January and February carry the heaviest snow load of the year in St. Louis, so per-occurrence costs and total seasonal spend concentrate there. Seasonal and Zero-Tolerance contracts are built to absorb that concentration instead of billing storm by storm.
One last thing
The four zero-snow months — June, July, August, September — aren't in the table because they're irrelevant. They're the reminder that a "per season" snow removal quote for 2026 is really pricing five months of real risk, not twelve. Any contract that spreads cost evenly across all twelve months is either padding the shoulder season or underpricing December and January.
