Gardiner Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Gardiner. 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 21 and the first fall freeze around September 27, a growing season of about 128 days.
- Median at 36°F
- last June 6, first September 16
- Median at 32°F
- last May 21, first September 27
- Median at 28°F
- last May 6, first October 7
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 22 | Jun 16 | Jun 12 | Jun 8 | Jun 6 | Jun 3 | Jun 1 | May 27 | May 20 |
| 32°F | Jun 9 | Jun 3 | May 29 | May 25 | May 21 | May 18 | May 14 | May 11 | May 5 |
| 28°F | May 23 | May 16 | May 12 | May 9 | May 6 | May 3 | Apr 30 | Apr 26 | Apr 20 |
| 24°F | May 9 | May 3 | Apr 30 | Apr 27 | Apr 23 | Apr 20 | Apr 15 | Apr 11 | Apr 4 |
| 20°F | Apr 27 | Apr 22 | Apr 17 | Apr 11 | Apr 7 | Apr 4 | Apr 1 | Mar 28 | Mar 18 |
| 16°F | Apr 16 | Apr 7 | Apr 3 | Mar 31 | Mar 26 | Mar 21 | Mar 17 | Mar 11 | Mar 4 |
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 2 | Sep 7 | Sep 10 | Sep 13 | Sep 16 | Sep 20 | Sep 22 | Sep 25 | Sep 30 |
| 32°F | Sep 12 | Sep 19 | Sep 23 | Sep 25 | Sep 27 | Sep 30 | Oct 2 | Oct 6 | Oct 11 |
| 28°F | Sep 25 | Sep 30 | Oct 2 | Oct 5 | Oct 7 | Oct 11 | Oct 14 | Oct 18 | Oct 23 |
| 24°F | Oct 2 | Oct 7 | Oct 11 | Oct 14 | Oct 18 | Oct 22 | Oct 25 | Oct 29 | Nov 3 |
| 20°F | Oct 13 | Oct 19 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 5 | Nov 8 | Nov 14 |
| 16°F | Oct 22 | Oct 27 | Oct 31 | Nov 3 | Nov 6 | Nov 10 | Nov 13 | Nov 17 | Nov 23 |
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 | 121 | 115 | 110 | 105 | 101 | 97 | 93 | 87 | 79 |
| 32°F | 149 | 142 | 136 | 132 | 128 | 124 | 120 | 114 | 105 |
| 28°F | 176 | 167 | 162 | 157 | 153 | 149 | 144 | 139 | 131 |
| 24°F | 203 | 194 | 188 | 183 | 178 | 174 | 168 | 163 | 154 |
| 20°F | 228 | 221 | 215 | 210 | 205 | 200 | 194 | 187 | 178 |
| 16°F | 250 | 242 | 236 | 231 | 226 | 221 | 216 | 211 | 202 |
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
- 7,194
- Cooling degree days, base 65°F
- 407
- Growing degree days, base 40°F
- 4,051
- Growing degree days, base 45°F
- 3,015
- Growing degree days, base 50°F
- 2,145
- Growing degree days, base 55°F
- 1,426
- Growing degree days, base 60°F
- 844
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,215 | 0 | 0 |
| February | 1,029 | 0 | 0 |
| March | 870 | 0 | 3 |
| April | 615 | 0 | 30 |
| May | 375 | 4 | 151 |
| June | 138 | 45 | 361 |
| July | 20 | 181 | 626 |
| August | 28 | 147 | 585 |
| September | 183 | 28 | 311 |
| October | 556 | 1 | 74 |
| November | 935 | 0 | 4 |
| December | 1,231 | 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 0.2 km from Gardiner. 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 USC00243378 (Gardiner). Public domain.