Silver Springs Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Lahontan Dam. 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 18 and the first fall freeze around October 25, a growing season of about 188 days.
- Median at 36°F
- last May 3, first October 14
- Median at 32°F
- last April 18, first October 25
- Median at 28°F
- last April 2, first November 4
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 30 | May 17 | May 11 | May 7 | May 3 | Apr 30 | Apr 26 | Apr 22 | Apr 17 |
| 32°F | May 9 | Apr 30 | Apr 26 | Apr 22 | Apr 18 | Apr 15 | Apr 12 | Apr 7 | Apr 2 |
| 28°F | Apr 20 | Apr 13 | Apr 10 | Apr 5 | Apr 2 | Mar 31 | Mar 24 | Mar 18 | Mar 11 |
| 24°F | Apr 5 | Mar 30 | Mar 23 | Mar 17 | Mar 13 | Mar 9 | Mar 5 | Feb 28 | Feb 22 |
| 20°F | Mar 18 | Mar 11 | Mar 6 | Mar 1 | Feb 26 | Feb 21 | Feb 16 | Feb 9 | Feb 2 |
| 16°F | Mar 7 | Feb 27 | Feb 19 | Feb 14 | Feb 8 | Feb 3 | Jan 26 | Jan 16 | Jan 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 | Oct 2 | Oct 6 | Oct 9 | Oct 12 | Oct 14 | Oct 17 | Oct 21 | Oct 24 | Oct 29 |
| 32°F | Oct 11 | Oct 15 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 3 | Nov 7 |
| 28°F | Oct 21 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 15 | Nov 20 |
| 24°F | Oct 29 | Nov 3 | Nov 7 | Nov 11 | Nov 16 | Nov 19 | Nov 22 | Nov 26 | Dec 1 |
| 20°F | Nov 6 | Nov 13 | Nov 19 | Nov 22 | Nov 26 | Nov 30 | Dec 3 | Dec 7 | Dec 16 |
| 16°F | Nov 18 | Nov 24 | Nov 30 | Dec 2 | Dec 6 | Dec 9 | Dec 15 | Dec 21 | Jan 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 | 186 | 178 | 172 | 167 | 162 | 158 | 153 | 146 | 135 |
| 32°F | 211 | 203 | 198 | 193 | 188 | 183 | 178 | 172 | 162 |
| 28°F | 243 | 232 | 225 | 219 | 214 | 209 | 204 | 198 | 190 |
| 24°F | 273 | 263 | 255 | 248 | 243 | 237 | 231 | 225 | 216 |
| 20°F | 305 | 293 | 283 | 278 | 272 | 266 | 261 | 252 | 244 |
| 16°F | 341 | 329 | 317 | 309 | 301 | 293 | 287 | 278 | 267 |
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
- 99% 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
- 4,521
- Cooling degree days, base 65°F
- 1,459
- Growing degree days, base 40°F
- 6,563
- Growing degree days, base 45°F
- 5,202
- Growing degree days, base 50°F
- 4,017
- Growing degree days, base 55°F
- 3,007
- Growing degree days, base 60°F
- 2,161
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 902 | 0 | 1 |
| February | 682 | 0 | 8 |
| March | 541 | 0 | 60 |
| April | 347 | 4 | 156 |
| May | 151 | 66 | 385 |
| June | 30 | 245 | 665 |
| July | 1 | 496 | 961 |
| August | 1 | 432 | 896 |
| September | 40 | 188 | 599 |
| October | 277 | 27 | 247 |
| November | 624 | 0 | 38 |
| December | 925 | 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 15 km from Silver 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 USC00264349 (Lahontan Dam). Public domain.