Concordia Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Sweet Springs. A median date has an even chance of a later freeze in spring, or an earlier one in fall.
The last spring freeze typically comes around April 17 and the first fall freeze around October 20, a growing season of about 184 days.
- Median at 36°F
- last April 28, first October 9
- Median at 32°F
- last April 17, first October 20
- Median at 28°F
- last April 4, first October 29
Last freeze in spring
The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 11 | May 6 | May 3 | Apr 30 | Apr 28 | Apr 25 | Apr 22 | Apr 18 | Apr 14 |
| 32°F | May 2 | Apr 27 | Apr 24 | Apr 20 | Apr 17 | Apr 13 | Apr 10 | Apr 7 | Apr 3 |
| 28°F | Apr 20 | Apr 14 | Apr 10 | Apr 8 | Apr 4 | Apr 1 | Mar 30 | Mar 25 | Mar 19 |
| 24°F | Apr 10 | Apr 4 | Mar 31 | Mar 28 | Mar 24 | Mar 21 | Mar 17 | Mar 12 | Mar 5 |
| 20°F | Mar 31 | Mar 25 | Mar 20 | Mar 16 | Mar 13 | Mar 9 | Mar 6 | Mar 2 | Feb 26 |
| 16°F | Mar 21 | Mar 16 | Mar 12 | Mar 8 | Mar 5 | Mar 2 | Feb 27 | Feb 23 | Feb 16 |
First freeze in fall
The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 24 | Sep 29 | Oct 3 | Oct 6 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 22 |
| 32°F | Oct 1 | Oct 9 | Oct 13 | Oct 16 | Oct 20 | Oct 22 | Oct 25 | Oct 28 | Nov 1 |
| 28°F | Oct 15 | Oct 21 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 2 | Nov 6 | Nov 10 |
| 24°F | Oct 26 | Oct 30 | Nov 2 | Nov 4 | Nov 6 | Nov 10 | Nov 13 | Nov 17 | Nov 22 |
| 20°F | Nov 3 | Nov 7 | Nov 11 | Nov 14 | Nov 17 | Nov 21 | Nov 25 | Nov 30 | Dec 5 |
| 16°F | Nov 9 | Nov 15 | Nov 20 | Nov 24 | Nov 28 | Dec 2 | Dec 6 | Dec 11 | Dec 18 |
Growing season length
Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.
| Threshold | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | 182 | 176 | 171 | 167 | 163 | 159 | 154 | 149 | 143 |
| 32°F | 205 | 198 | 193 | 188 | 184 | 180 | 175 | 170 | 162 |
| 28°F | 227 | 220 | 215 | 211 | 207 | 203 | 199 | 194 | 186 |
| 24°F | 252 | 243 | 237 | 233 | 228 | 224 | 219 | 213 | 207 |
| 20°F | 274 | 265 | 260 | 255 | 250 | 245 | 241 | 235 | 227 |
| 16°F | 292 | 285 | 279 | 273 | 268 | 264 | 258 | 252 | 244 |
How often it gets that cold
The share of years with at least one night at or below each temperature.
- 36°F or colder
- 100% of years
- 32°F or colder
- 100% of years
- 28°F or colder
- 100% of years
- 24°F or colder
- 100% of years
- 20°F or colder
- 100% of years
- 16°F or colder
- 100% of years
Degree days
A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.
- Heating degree days, base 65°F
- 5,162
- Cooling degree days, base 65°F
- 1,284
- Growing degree days, base 40°F
- 6,336
- Growing degree days, base 45°F
- 5,063
- Growing degree days, base 50°F
- 3,921
- Growing degree days, base 55°F
- 2,910
- Growing degree days, base 60°F
- 2,029
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,150 | 0 | 2 |
| February | 888 | 0 | 12 |
| March | 655 | 3 | 65 |
| April | 343 | 17 | 195 |
| May | 112 | 97 | 453 |
| June | 9 | 265 | 706 |
| July | 1 | 393 | 857 |
| August | 2 | 340 | 803 |
| September | 62 | 143 | 533 |
| October | 306 | 25 | 235 |
| November | 648 | 1 | 53 |
| December | 987 | 0 | 8 |
What this means
NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.
The station is 13.1 km from Concordia. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.
More
Sources
NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00238223 (Sweet Springs). Public domain.