Fremont Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Fremont 4 Wsw. 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 8 and the first fall freeze around October 11, a growing season of about 155 days.
- Median at 36°F
- last May 21, first October 1
- Median at 32°F
- last May 8, first October 11
- Median at 28°F
- last April 27, first October 25
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 3 | May 30 | May 27 | May 24 | May 21 | May 19 | May 15 | May 11 | May 6 |
| 32°F | May 25 | May 20 | May 16 | May 12 | May 8 | May 5 | May 2 | Apr 29 | Apr 24 |
| 28°F | May 14 | May 7 | May 3 | Apr 30 | Apr 27 | Apr 23 | Apr 20 | Apr 17 | Apr 11 |
| 24°F | May 1 | Apr 24 | Apr 20 | Apr 17 | Apr 14 | Apr 10 | Apr 7 | Apr 3 | Mar 30 |
| 20°F | Apr 16 | Apr 10 | Apr 7 | Apr 4 | Apr 2 | Mar 31 | Mar 28 | Mar 23 | Mar 17 |
| 16°F | Apr 6 | Apr 1 | Mar 30 | Mar 27 | Mar 24 | Mar 21 | Mar 18 | Mar 14 | Mar 6 |
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 18 | Sep 23 | Sep 27 | Sep 30 | Oct 1 | Oct 4 | Oct 6 | Oct 9 | Oct 13 |
| 32°F | Sep 30 | Oct 3 | Oct 6 | Oct 9 | Oct 11 | Oct 14 | Oct 16 | Oct 20 | Oct 25 |
| 28°F | Oct 11 | Oct 15 | Oct 19 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 8 |
| 24°F | Oct 27 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 18 | Nov 25 |
| 20°F | Nov 6 | Nov 11 | Nov 15 | Nov 18 | Nov 22 | Nov 25 | Nov 30 | Dec 3 | Dec 9 |
| 16°F | Nov 15 | Nov 22 | Nov 26 | Nov 30 | Dec 3 | Dec 6 | Dec 11 | Dec 16 | Dec 22 |
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 | 152 | 145 | 141 | 137 | 132 | 128 | 125 | 120 | 113 |
| 32°F | 176 | 168 | 162 | 158 | 155 | 151 | 147 | 142 | 134 |
| 28°F | 200 | 193 | 188 | 184 | 180 | 175 | 171 | 166 | 159 |
| 24°F | 231 | 223 | 217 | 213 | 208 | 204 | 199 | 194 | 187 |
| 20°F | 258 | 249 | 243 | 238 | 233 | 228 | 224 | 220 | 213 |
| 16°F | 278 | 271 | 265 | 260 | 255 | 250 | 244 | 239 | 231 |
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
- 7,190
- Cooling degree days, base 65°F
- 389
- Growing degree days, base 40°F
- 4,200
- Growing degree days, base 45°F
- 3,169
- Growing degree days, base 50°F
- 2,272
- Growing degree days, base 55°F
- 1,499
- Growing degree days, base 60°F
- 860
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,313 | 0 | 0 |
| February | 1,148 | 0 | 0 |
| March | 1,004 | 1 | 13 |
| April | 627 | 0 | 46 |
| May | 309 | 16 | 214 |
| June | 73 | 80 | 458 |
| July | 27 | 143 | 581 |
| August | 38 | 105 | 532 |
| September | 171 | 42 | 329 |
| October | 501 | 2 | 91 |
| November | 831 | 0 | 8 |
| December | 1,149 | 0 | 0 |
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 7.2 km from Fremont. 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 USC00203025 (Fremont 4 Wsw). Public domain.