Cameron County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Emporium. 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 7 and the first fall freeze around October 15, a growing season of about 160 days.
- Median at 36°F
- last May 19, first October 3
- Median at 32°F
- last May 7, first October 15
- Median at 28°F
- last April 27, first October 28
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 31 | May 28 | May 25 | May 22 | May 19 | May 16 | May 12 | May 9 | May 2 |
| 32°F | May 23 | May 18 | May 13 | May 10 | May 7 | May 3 | Apr 30 | Apr 27 | Apr 23 |
| 28°F | May 13 | May 7 | May 3 | Apr 30 | Apr 27 | Apr 23 | Apr 20 | Apr 17 | Apr 11 |
| 24°F | May 2 | Apr 23 | Apr 18 | Apr 16 | Apr 13 | Apr 9 | Apr 6 | Apr 4 | Mar 31 |
| 20°F | Apr 11 | Apr 7 | Apr 4 | Apr 2 | Apr 1 | Mar 30 | Mar 26 | Mar 22 | Mar 17 |
| 16°F | Apr 3 | Mar 31 | Mar 28 | Mar 25 | Mar 22 | Mar 19 | Mar 15 | Mar 12 | Mar 8 |
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 20 | Sep 25 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 8 | Oct 12 | Oct 16 |
| 32°F | Oct 1 | Oct 5 | Oct 8 | Oct 12 | Oct 15 | Oct 18 | Oct 22 | Oct 26 | Nov 1 |
| 28°F | Oct 13 | Oct 17 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 1 | Nov 5 | Nov 9 |
| 24°F | Oct 24 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 9 | Nov 12 | Nov 15 | Nov 18 |
| 20°F | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 20 | Nov 24 | Nov 27 | Dec 3 |
| 16°F | Nov 11 | Nov 16 | Nov 20 | Nov 24 | Nov 28 | Dec 1 | Dec 5 | Dec 10 | Dec 16 |
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 | 157 | 150 | 145 | 141 | 137 | 133 | 129 | 125 | 118 |
| 32°F | 182 | 174 | 169 | 164 | 160 | 155 | 151 | 146 | 138 |
| 28°F | 203 | 196 | 191 | 187 | 183 | 178 | 175 | 170 | 161 |
| 24°F | 227 | 221 | 216 | 212 | 208 | 204 | 200 | 193 | 186 |
| 20°F | 253 | 245 | 239 | 235 | 232 | 228 | 223 | 219 | 214 |
| 16°F | 273 | 267 | 260 | 255 | 250 | 246 | 242 | 237 | 229 |
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
- 6,562
- Cooling degree days, base 65°F
- 508
- Growing degree days, base 40°F
- 4,630
- Growing degree days, base 45°F
- 3,529
- Growing degree days, base 50°F
- 2,563
- Growing degree days, base 55°F
- 1,738
- Growing degree days, base 60°F
- 1,043
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,252 | 0 | 0 |
| February | 1,078 | 0 | 0 |
| March | 924 | 0 | 9 |
| April | 545 | 2 | 70 |
| May | 249 | 31 | 265 |
| June | 62 | 106 | 494 |
| July | 9 | 175 | 631 |
| August | 15 | 145 | 595 |
| September | 125 | 47 | 376 |
| October | 450 | 4 | 108 |
| November | 770 | 0 | 14 |
| December | 1,083 | 0 | 2 |
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 8 km from Cameron County. 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 USC00362629 (Emporium). Public domain.