Rapides Parish Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Alexandria 5 Sse. 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 March 3 and the first fall freeze around November 22, a growing season of about 263 days.
- Median at 36°F
- last March 19, first November 8
- Median at 32°F
- last March 3, first November 22
- Median at 28°F
- last February 16, first December 7
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 | Apr 7 | Apr 2 | Mar 30 | Mar 25 | Mar 19 | Mar 15 | Mar 9 | Mar 4 | Feb 26 |
| 32°F | Mar 24 | Mar 17 | Mar 12 | Mar 8 | Mar 3 | Feb 28 | Feb 23 | Feb 16 | Feb 4 |
| 28°F | Mar 13 | Mar 6 | Feb 28 | Feb 23 | Feb 16 | Feb 7 | Jan 31 | Jan 26 | Jan 13 |
| 24°F | Mar 1 | Feb 17 | Feb 8 | Feb 1 | Jan 28 | Jan 24 | Jan 15 | Jan 5 | Dec 27 |
| 20°F | Feb 7 | Feb 1 | Jan 30 | Jan 24 | Jan 17 | Jan 11 | Jan 4 | Dec 29 | Dec 20 |
| 16°F | Feb 2 | Jan 31 | Jan 29 | Jan 23 | Jan 19 | Jan 15 | Jan 9 | Jan 5 | Jan 2 |
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 | Oct 26 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 12 | Nov 16 | Nov 21 | Dec 1 |
| 32°F | Nov 3 | Nov 8 | Nov 13 | Nov 18 | Nov 22 | Nov 27 | Dec 1 | Dec 4 | Dec 11 |
| 28°F | Nov 15 | Nov 24 | Nov 30 | Dec 3 | Dec 7 | Dec 12 | Dec 21 | Dec 29 | Jan 6 |
| 24°F | Dec 1 | Dec 6 | Dec 15 | Dec 23 | Dec 29 | Jan 1 | Jan 5 | Jan 13 | Jan 29 |
| 20°F | Dec 10 | Dec 21 | Dec 27 | Jan 1 | Jan 4 | Jan 8 | Jan 15 | Jan 21 | Feb 1 |
| 16°F | Jan 1 | Jan 4 | Jan 7 | Jan 10 | Jan 15 | Jan 19 | Jan 25 | Jan 29 | Feb 1 |
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 | 265 | 253 | 246 | 241 | 236 | 231 | 225 | 219 | 210 |
| 32°F | 297 | 286 | 278 | 270 | 263 | 257 | 251 | 245 | 236 |
| 28°F | 334 | 322 | 312 | 306 | 298 | 289 | 281 | 271 | 260 |
| 24°F | 365 | 360 | 349 | 341 | 334 | 326 | 316 | 307 | 297 |
| 20°F | 365 | 365 | 365 | 365 | 365 | 362 | 353 | 342 | 330 |
| 16°F | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 365 | 363 |
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
- 99% of years
- 24°F or colder
- 85% of years
- 20°F or colder
- 44% of years
- 16°F or colder
- 12% 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
- 1,925
- Cooling degree days, base 65°F
- 2,622
- Growing degree days, base 40°F
- 9,882
- Growing degree days, base 45°F
- 8,167
- Growing degree days, base 50°F
- 6,563
- Growing degree days, base 55°F
- 5,093
- Growing degree days, base 60°F
- 3,771
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 505 | 8 | 114 |
| February | 359 | 16 | 154 |
| March | 208 | 45 | 326 |
| April | 72 | 112 | 493 |
| May | 7 | 297 | 755 |
| June | 0 | 462 | 912 |
| July | 0 | 547 | 1,012 |
| August | 0 | 550 | 1,015 |
| September | 2 | 392 | 840 |
| October | 64 | 153 | 554 |
| November | 250 | 28 | 257 |
| December | 459 | 12 | 133 |
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 9.7 km from Rapides Parish. 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 USC00160103 (Alexandria 5 Sse). Public domain.