Austin Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Coudersport 1 Sw. 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 May 22 and the first fall freeze around October 1, a growing season of about 130 days.
- Median at 36°F
- last June 3, first September 21
- Median at 32°F
- last May 22, first October 1
- Median at 28°F
- last May 9, first October 11
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 | Jun 28 | Jun 16 | Jun 11 | Jun 7 | Jun 3 | May 31 | May 29 | May 25 | May 20 |
| 32°F | Jun 6 | Jun 1 | May 29 | May 26 | May 22 | May 19 | May 15 | May 10 | May 6 |
| 28°F | May 28 | May 21 | May 16 | May 12 | May 9 | May 5 | May 1 | Apr 29 | Apr 24 |
| 24°F | May 15 | May 8 | May 3 | Apr 30 | Apr 26 | Apr 23 | Apr 20 | Apr 17 | Apr 12 |
| 20°F | Apr 30 | Apr 23 | Apr 20 | Apr 17 | Apr 15 | Apr 12 | Apr 8 | Apr 4 | Mar 31 |
| 16°F | Apr 18 | Apr 12 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 28 | Mar 24 | Mar 19 |
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 2 | Sep 8 | Sep 14 | Sep 18 | Sep 21 | Sep 24 | Sep 27 | Sep 30 | Oct 3 |
| 32°F | Sep 19 | Sep 23 | Sep 27 | Sep 29 | Oct 1 | Oct 3 | Oct 5 | Oct 9 | Oct 13 |
| 28°F | Sep 29 | Oct 2 | Oct 6 | Oct 8 | Oct 11 | Oct 14 | Oct 18 | Oct 22 | Oct 28 |
| 24°F | Oct 8 | Oct 14 | Oct 18 | Oct 21 | Oct 25 | Oct 28 | Nov 1 | Nov 3 | Nov 7 |
| 20°F | Oct 18 | Oct 25 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 15 | Nov 20 |
| 16°F | Oct 31 | Nov 4 | Nov 9 | Nov 13 | Nov 16 | Nov 20 | Nov 23 | Nov 28 | Dec 3 |
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 | 128 | 121 | 115 | 111 | 107 | 102 | 96 | 87 | 75 |
| 32°F | 152 | 145 | 139 | 135 | 130 | 126 | 122 | 117 | 110 |
| 28°F | 176 | 170 | 165 | 160 | 155 | 150 | 145 | 139 | 131 |
| 24°F | 202 | 194 | 189 | 185 | 180 | 175 | 170 | 164 | 156 |
| 20°F | 227 | 218 | 213 | 209 | 205 | 200 | 195 | 190 | 182 |
| 16°F | 249 | 243 | 237 | 232 | 228 | 223 | 219 | 213 | 206 |
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
- 7,472
- Cooling degree days, base 65°F
- 249
- Growing degree days, base 40°F
- 3,881
- Growing degree days, base 45°F
- 2,860
- Growing degree days, base 50°F
- 1,974
- Growing degree days, base 55°F
- 1,229
- Growing degree days, base 60°F
- 645
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,334 | 0 | 0 |
| February | 1,159 | 0 | 0 |
| March | 1,028 | 0 | 6 |
| April | 638 | 0 | 44 |
| May | 330 | 12 | 192 |
| June | 116 | 46 | 382 |
| July | 44 | 97 | 518 |
| August | 58 | 72 | 479 |
| September | 207 | 21 | 273 |
| October | 546 | 2 | 75 |
| November | 855 | 0 | 5 |
| December | 1,158 | 0 | 1 |
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 14.8 km from Austin. 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 USC00361802 (Coudersport 1 Sw). Public domain.