Americus Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Emporia 3 Nw. 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 15 and the first fall freeze around October 23, a growing season of about 190 days.
- Median at 36°F
- last April 26, first October 13
- Median at 32°F
- last April 15, first October 23
- Median at 28°F
- last April 5, first November 1
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 8 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 22 | Apr 19 | Apr 16 | Apr 11 |
| 32°F | Apr 30 | Apr 24 | Apr 21 | Apr 18 | Apr 15 | Apr 13 | Apr 9 | Apr 5 | Apr 2 |
| 28°F | Apr 21 | Apr 15 | Apr 11 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 27 | Mar 21 |
| 24°F | Apr 10 | Apr 5 | Apr 2 | Mar 31 | Mar 28 | Mar 24 | Mar 20 | Mar 15 | Mar 7 |
| 20°F | Apr 2 | Mar 28 | Mar 23 | Mar 19 | Mar 15 | Mar 11 | Mar 6 | Mar 3 | Feb 26 |
| 16°F | Mar 22 | Mar 15 | Mar 11 | Mar 7 | Mar 3 | Mar 1 | Feb 26 | Feb 21 | Feb 14 |
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 28 | Oct 3 | Oct 7 | Oct 11 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 |
| 32°F | Oct 8 | Oct 14 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 5 |
| 28°F | Oct 18 | Oct 23 | Oct 27 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 17 |
| 24°F | Oct 28 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 21 | Nov 28 |
| 20°F | Nov 2 | Nov 7 | Nov 12 | Nov 15 | Nov 20 | Nov 23 | Nov 28 | Dec 1 | Dec 8 |
| 16°F | Nov 10 | Nov 16 | Nov 21 | Nov 25 | Nov 29 | Dec 3 | Dec 7 | 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 | 190 | 183 | 177 | 173 | 169 | 165 | 161 | 156 | 150 |
| 32°F | 210 | 203 | 199 | 194 | 190 | 187 | 182 | 176 | 169 |
| 28°F | 231 | 223 | 218 | 214 | 210 | 206 | 202 | 197 | 190 |
| 24°F | 253 | 244 | 238 | 233 | 228 | 224 | 219 | 214 | 207 |
| 20°F | 273 | 265 | 259 | 254 | 248 | 243 | 237 | 231 | 223 |
| 16°F | 293 | 285 | 279 | 275 | 269 | 263 | 257 | 251 | 241 |
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
- 5,284
- Cooling degree days, base 65°F
- 1,235
- Growing degree days, base 40°F
- 6,173
- Growing degree days, base 45°F
- 4,912
- Growing degree days, base 50°F
- 3,786
- Growing degree days, base 55°F
- 2,801
- Growing degree days, base 60°F
- 1,953
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,124 | 0 | 1 |
| February | 895 | 0 | 6 |
| March | 681 | 2 | 53 |
| April | 375 | 10 | 166 |
| May | 136 | 74 | 409 |
| June | 11 | 247 | 685 |
| July | 1 | 393 | 857 |
| August | 3 | 343 | 804 |
| September | 68 | 144 | 529 |
| October | 315 | 22 | 228 |
| November | 668 | 1 | 45 |
| December | 1,009 | 0 | 4 |
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 9.4 km from Americus. 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 USC00142548 (Emporia 3 Nw). Public domain.