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Will it freeze in St. Charles in the next 7 nights?
No overnight lows at or below 32°F are forecast in St. Charles during the next 7 nights in the available NWS frost forecast.
Tonight: forecast low 45°F. Above 36°F.
NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.
2 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 45°F Above 36°F · Slight Chance Drizzle then Cloudy
- Fri, Nov 6 34°F Frost possible · Mostly Clear
- Sat, Nov 7 35°F Frost possible · Mostly Clear
- Sun, Nov 8 38°F Above 36°F · Clear
- Mon, Nov 9 43°F Above 36°F · Clear
- Tue, Nov 10 43°F Above 36°F · Mostly Clear
- Wed, Nov 11 44°F Above 36°F · Mostly Clear
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in St. Charles
The median first fall hard-freeze date (28°F) is November 10, from NOAA’s 1991–2020 Climate Normals at St Charles Elm Point. This is the 50% probability date, not a forecast for this year.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | Apr 5 · Apr 21 · May 5 | Oct 7 · Oct 19 · Oct 31 | 180 days |
| 32°F freeze | Mar 23 · Apr 8 · Apr 24 | Oct 16 · Oct 29 · Nov 12 | 203 days |
| 28°F hard freeze | Mar 9 · Mar 30 · Apr 15 | Oct 29 · Nov 10 · Nov 28 | 225 days |
Average high temperature by month
1991–2020 normals at St Charles Elm Point
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for St. Charles, MO come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: St Charles Elm Point (station USC00237397, elevation 472 ft), 1.3 mi from St. Charles. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near St. Charles
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| St. Peters, MO | 5.0 mi | Apr 9 | Oct 26 |
| Bridgeton, MO | 5.6 mi | Apr 2 | Nov 4 |
| Maryland Heights, MO | 6.2 mi | Apr 4 | Oct 29 |
| Hazelwood, MO | 6.2 mi | Apr 2 | Nov 4 |
| Cottleville, MO | 8.1 mi | Apr 9 | Oct 26 |
| St. Ann, MO | 8.7 mi | Apr 2 | Nov 4 |
| Weldon Spring, MO | 9.3 mi | Apr 10 | Oct 26 |
| Creve Coeur, MO | 9.9 mi | Apr 4 | Oct 29 |
| Chesterfield, MO | 9.9 mi | Apr 4 | Oct 29 |
| Florissant, MO | 9.9 mi | Apr 2 | Nov 4 |
Frequently asked questions
When is the last frost in St. Charles?
On average, the last spring frost (32°F) in St. Charles is around April 8. In about 1 year in 10 it comes after April 24, and in 9 years in 10 it comes after March 23.
When is the first frost in St. Charles?
The first fall frost (32°F) usually arrives around October 29. There’s a 10% chance of a freeze by October 16 and a 90% chance by November 12.
Can it frost in St. Charles after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after April 21.
What growing zone is St. Charles?
St. Charles is in USDA Plant Hardiness Zone 6b (average annual extreme minimum temperature −5 to 0°F), based on the 2023 USDA map for ZIP code 63045. See growing zones in Missouri.
More: all Missouri frost dates · Missouri growing zones · UV index today in St. Charles · frost vs. freeze