Frost dates for St. Louis Lambert Intl Airport, MO
At St. Louis Lambert Intl Airport, the median last spring frost (32°F) is Apr 2 and the median first fall frost is Nov 4, for a typical growing season of 215 days. For a 90% chance that the last frost has passed, wait until Apr 17. Nearby ZIP codes are in USDA hardiness zones 6b to 7a.
- Apr 2Last spring frost (median)50% chance of 32°F after this date
- Apr 17Safer planting date10% chance of 32°F after this date
- Nov 4First fall frost (median)50% chance of 32°F by this date
- 215 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Mar 31 | Apr 13 | Apr 28 |
| 32°F | Mar 17 | Apr 2 | Apr 17 |
| 28°F | Mar 5 | Mar 23 | Apr 7 |
| 24°F | Feb 24 | Mar 12 | Mar 29 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Oct 14 | Oct 26 | Nov 6 |
| 32°F | Oct 23 | Nov 4 | Nov 18 |
| 28°F | Nov 2 | Nov 13 | Nov 30 |
| 24°F | Nov 8 | Nov 24 | Dec 11 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 176 days | 195 days | 213 days |
| 32°F | 196 days | 215 days | 236 days |
| 28°F | 216 days | 236 days | 258 days |
| 24°F | 232 days | 254 days | 277 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 63134 | 7a | 0 to 5°F | 3 km |
| 63074 | 7a | 0 to 5°F | 3 km |
| 63042 | 7a | 0 to 5°F | 3 km |
| 63140 | 7a | 0 to 5°F | 5 km |
| 63044 | 6b | -5 to 0°F | 5 km |
| 63114 | 7a | 0 to 5°F | 6 km |
| 63135 | 7a | 0 to 5°F | 6 km |
| 63031 | 7a | 0 to 5°F | 7 km |
| 63043 | 7a | 0 to 5°F | 8 km |
| 63121 | 7a | 0 to 5°F | 8 km |
| 63132 | 7a | 0 to 5°F | 9 km |
| 63136 | 7a | 0 to 5°F | 10 km |
| 63033 | 7a | 0 to 5°F | 10 km |
| 63137 | 7a | 0 to 5°F | 14 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USW00013994, at 38.7525, -90.3736, elevation 162 m (531 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 85.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- St. Charles Elm Point (14 km)
- St. Charles 7 SSW (15 km)
- St. Louis Sci Center (16 km)
- St. Peters 2 SE (19 km)
- St. Charles Co Airport (20 km)
- St. Louis Sprt Of S L Airport (27 km)
- Weldon Spring NWS (27 km)
- Elsberry 1 S (57 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.