Lyon County Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Yerington. 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 29 and the first fall freeze around October 15, a growing season of about 167 days.
- Median at 36°F
- last May 14, first October 4
- Median at 32°F
- last April 29, first October 15
- Median at 28°F
- last April 13, first October 26
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 4 | May 30 | May 24 | May 20 | May 14 | May 11 | May 6 | May 2 | Apr 28 |
| 32°F | May 16 | May 11 | May 6 | May 2 | Apr 29 | Apr 26 | Apr 22 | Apr 19 | Apr 13 |
| 28°F | May 2 | Apr 25 | Apr 21 | Apr 18 | Apr 13 | Apr 10 | Apr 6 | Apr 2 | Mar 25 |
| 24°F | Apr 16 | Apr 7 | Apr 3 | Mar 30 | Mar 26 | Mar 20 | Mar 15 | Mar 10 | Mar 3 |
| 20°F | Mar 25 | Mar 18 | Mar 12 | Mar 8 | Mar 4 | Feb 28 | Feb 24 | Feb 19 | Feb 9 |
| 16°F | Mar 9 | Mar 1 | Feb 26 | Feb 20 | Feb 15 | Feb 10 | Feb 3 | Jan 28 | Jan 12 |
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 21 | Sep 26 | Sep 30 | Oct 2 | Oct 4 | Oct 7 | Oct 9 | Oct 13 | Oct 18 |
| 32°F | Sep 30 | Oct 4 | Oct 7 | Oct 12 | Oct 15 | Oct 17 | Oct 20 | Oct 24 | Oct 27 |
| 28°F | Oct 11 | Oct 16 | Oct 20 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 2 | Nov 6 |
| 24°F | Oct 21 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 17 |
| 20°F | Oct 28 | Nov 2 | Nov 6 | Nov 10 | Nov 13 | Nov 17 | Nov 20 | Nov 23 | Nov 27 |
| 16°F | Nov 9 | Nov 14 | Nov 19 | Nov 22 | Nov 25 | Nov 28 | Dec 1 | Dec 4 | Dec 11 |
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 | 162 | 155 | 151 | 146 | 142 | 138 | 133 | 126 | 118 |
| 32°F | 188 | 180 | 175 | 170 | 167 | 163 | 158 | 153 | 145 |
| 28°F | 214 | 207 | 202 | 197 | 191 | 187 | 182 | 176 | 167 |
| 24°F | 247 | 239 | 232 | 226 | 220 | 215 | 209 | 204 | 197 |
| 20°F | 278 | 269 | 262 | 257 | 251 | 246 | 240 | 233 | 224 |
| 16°F | 319 | 305 | 296 | 288 | 282 | 276 | 269 | 262 | 253 |
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
- 5,090
- Cooling degree days, base 65°F
- 922
- Growing degree days, base 40°F
- 5,619
- Growing degree days, base 45°F
- 4,338
- Growing degree days, base 50°F
- 3,240
- Growing degree days, base 55°F
- 2,314
- Growing degree days, base 60°F
- 1,548
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 953 | 0 | 1 |
| February | 745 | 0 | 2 |
| March | 603 | 0 | 37 |
| April | 418 | 1 | 106 |
| May | 201 | 34 | 311 |
| June | 47 | 152 | 556 |
| July | 2 | 343 | 806 |
| August | 4 | 289 | 750 |
| September | 62 | 98 | 488 |
| October | 353 | 6 | 167 |
| November | 711 | 0 | 16 |
| December | 992 | 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 3.6 km from Lyon 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 USC00269229 (Yerington). Public domain.