Last spring frost
Apr 11
Frost Dates for Linn, MO
First fall frost
Oct 21
Growing season
191 days
Hardiness zone
6b
In an average year around Linn, MO, the last spring frost (32°F) is about Apr 11 and the first fall frost is about Oct 21, giving roughly a 191-day growing season. To be safe most years, wait until Mar 28 before setting out tender plants.
Last spring frost
Dates the last frost of spring typically ends. Plant tender crops after the risk has passed for your comfort level.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | May 14 | Apr 27 | Apr 10 |
| Freeze (32°F) | Apr 30 | Apr 11 | Mar 28 |
| Hard (28°F) | Apr 19 | Mar 31 | Mar 14 |
| Severe (24°F) | Apr 5 | Mar 20 | Mar 2 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 14 | May 8 | May 4 | Apr 30 | Apr 27 | Apr 23 | Apr 19 | Apr 15 | Apr 10 |
| 32°F | Apr 30 | Apr 25 | Apr 20 | Apr 15 | Apr 11 | Apr 8 | Apr 5 | Apr 1 | Mar 28 |
| 28°F | Apr 19 | Apr 11 | Apr 6 | Apr 3 | Mar 31 | Mar 28 | Mar 25 | Mar 20 | Mar 14 |
| 24°F | Apr 5 | Mar 31 | Mar 27 | Mar 24 | Mar 20 | Mar 17 | Mar 13 | Mar 9 | Mar 2 |
| 20°F | Mar 28 | Mar 21 | Mar 17 | Mar 13 | Mar 9 | Mar 5 | Mar 2 | Feb 26 | Feb 20 |
| 16°F | Mar 18 | Mar 13 | Mar 8 | Mar 5 | Mar 2 | Feb 28 | Feb 24 | Feb 17 | Feb 10 |
First fall frost
Dates the first frost of fall typically arrives. Count back by a crop's days-to-maturity to know your planting cutoff.
| Frost intensity | Early (10%) | Average (50%) | Late (90%) |
|---|---|---|---|
| Light (36°F) | Sep 28 | Oct 12 | Oct 25 |
| Freeze (32°F) | Oct 6 | Oct 21 | Nov 4 |
| Hard (28°F) | Oct 18 | Nov 1 | Nov 16 |
| Severe (24°F) | Oct 31 | Nov 11 | Dec 1 |
Show full probability table (all thresholds & percentiles)
| °F | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 28 | Oct 2 | Oct 6 | Oct 9 | Oct 12 | Oct 15 | Oct 17 | Oct 20 | Oct 25 |
| 32°F | Oct 6 | Oct 12 | Oct 15 | Oct 18 | Oct 21 | Oct 25 | Oct 27 | Oct 30 | Nov 4 |
| 28°F | Oct 18 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 16 |
| 24°F | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 15 | Nov 19 | Nov 24 | Dec 1 |
| 20°F | Nov 6 | Nov 12 | Nov 16 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 11 |
| 16°F | Nov 14 | Nov 23 | Nov 26 | Nov 30 | Dec 3 | Dec 7 | Dec 10 | Dec 16 | Dec 23 |
Growing season is measured at 32°F with about 50% probability. Hardiness zone from the 2023 USDA map; frost normals from NOAA 1991-2020.
Where this data comes from
@endif These dates are computed from the nearest official weather station with long-term records: Freedom, Mo, about 3.8 miles away@if(!empty($station['elevation_ft'])), at 805 ft elevation. The further the station and the greater the elevation difference from your yard, the more your local frost timing can vary.
How we calculate these dates
Frost and freeze dates come from the NOAA 1991–2020 U.S. Climate Normals, the National Oceanic and Atmospheric Administration's 30-year averages for each weather station. A date shown at the 50% level is the median: in half of years the frost falls on or before it. The 10% and 90% columns show the early and late ends of the range, so you can plant on the odds you're comfortable with. These are long-term averages, not a forecast for this year - always check your local outlook before planting.
Source: NOAA National Centers for Environmental Information, 1991–2020 Climate Normals (public domain). Harman is not affiliated with or endorsed by NOAA.
Frequently asked questions
When is the last frost in Linn, MO?
On average, the last spring frost (32°F) around Linn, MO is about Apr 11. In cooler years it can run later, so for a safer bet many gardeners wait until Mar 28.
When is the first frost in the fall?
The first fall frost around Linn, MO typically arrives about Oct 21. Count back by a crop's days to maturity to find the latest date you can plant it.
When can I plant tomatoes and other tender crops?
Tender crops like tomatoes, peppers and basil are damaged by frost, so wait until the last spring frost has passed - around Apr 11 on average, or Mar 28 to be safe most years.
How long is the growing season here?
The frost-free growing season (between the last spring and first fall 32°F frost) is about 191 days in a typical year.
Are these dates a forecast for this year?
No. They are 30-year averages from the NOAA 1991–2020 Climate Normals, not a prediction for the current year. Use them for planning and always check your local weather forecast before planting or protecting crops.
Local weather for 65062 Planting calendar → Missouri frost dates →
Data source: NOAA 1991–2020 Climate Normals · Page updated Aug 4, 2026