Spanish Springs Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Spanish 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 May 3 and the first fall freeze around October 10, a growing season of about 157 days.
- Median at 36°F
- last May 20, first September 27
- Median at 32°F
- last May 3, first October 10
- Median at 28°F
- last April 20, first October 22
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 6 | Jun 1 | May 29 | May 24 | May 20 | May 16 | May 12 | May 9 | May 4 |
| 32°F | May 24 | May 17 | May 11 | May 6 | May 3 | Apr 30 | Apr 27 | Apr 24 | Apr 19 |
| 28°F | May 11 | May 1 | Apr 27 | Apr 23 | Apr 20 | Apr 17 | Apr 14 | Apr 10 | Apr 6 |
| 24°F | Apr 18 | Apr 13 | Apr 9 | Apr 6 | Apr 3 | Mar 31 | Mar 27 | Mar 21 | Mar 13 |
| 20°F | Apr 5 | Mar 29 | Mar 24 | Mar 17 | Mar 12 | Mar 8 | Mar 5 | Mar 1 | Feb 23 |
| 16°F | Mar 15 | Mar 8 | Mar 3 | Feb 28 | Feb 26 | Feb 22 | Feb 17 | Feb 11 | Feb 3 |
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 14 | Sep 19 | Sep 23 | Sep 25 | Sep 27 | Oct 1 | Oct 3 | Oct 5 | Oct 10 |
| 32°F | Sep 27 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 12 | Oct 15 | Oct 18 | Oct 23 |
| 28°F | Oct 7 | Oct 12 | Oct 15 | Oct 18 | Oct 22 | Oct 25 | Oct 29 | Nov 1 | Nov 4 |
| 24°F | Oct 19 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 |
| 20°F | Oct 30 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 16 | Nov 19 | Nov 23 | Nov 28 |
| 16°F | Nov 7 | Nov 13 | Nov 17 | Nov 21 | Nov 25 | Nov 29 | Dec 2 | Dec 7 | Dec 15 |
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 | 151 | 145 | 138 | 134 | 130 | 125 | 120 | 114 | 105 |
| 32°F | 176 | 170 | 166 | 161 | 157 | 154 | 149 | 142 | 134 |
| 28°F | 202 | 196 | 191 | 187 | 182 | 178 | 174 | 169 | 161 |
| 24°F | 236 | 226 | 220 | 215 | 212 | 206 | 202 | 195 | 190 |
| 20°F | 271 | 260 | 254 | 247 | 243 | 237 | 231 | 225 | 216 |
| 16°F | 305 | 293 | 285 | 280 | 274 | 268 | 262 | 256 | 248 |
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
- 5,373
- Cooling degree days, base 65°F
- 673
- Growing degree days, base 40°F
- 5,111
- Growing degree days, base 45°F
- 3,861
- Growing degree days, base 50°F
- 2,801
- Growing degree days, base 55°F
- 1,941
- Growing degree days, base 60°F
- 1,236
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 964 | 0 | 0 |
| February | 760 | 0 | 2 |
| March | 656 | 0 | 17 |
| April | 474 | 0 | 69 |
| May | 248 | 16 | 248 |
| June | 68 | 94 | 478 |
| July | 3 | 278 | 740 |
| August | 4 | 222 | 683 |
| September | 91 | 59 | 423 |
| October | 400 | 3 | 128 |
| November | 725 | 0 | 12 |
| December | 981 | 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 1.3 km from Spanish Springs. 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 USC00267691 (Spanish Springs). Public domain.