Moro Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Moro. 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 12 and the first fall freeze around October 4, a growing season of about 143 days.
- Median at 36°F
- last June 5, first September 19
- Median at 32°F
- last May 12, first October 4
- Median at 28°F
- last April 26, first October 16
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 30 | Jun 21 | Jun 15 | Jun 10 | Jun 5 | May 31 | May 27 | May 22 | May 16 |
| 32°F | May 31 | May 24 | May 20 | May 15 | May 12 | May 8 | May 5 | May 1 | Apr 27 |
| 28°F | May 11 | May 5 | May 1 | Apr 29 | Apr 26 | Apr 23 | Apr 19 | Apr 14 | Apr 8 |
| 24°F | Apr 25 | Apr 16 | Apr 11 | Apr 6 | Apr 3 | Mar 29 | Mar 24 | Mar 17 | Mar 9 |
| 20°F | Apr 3 | Mar 27 | Mar 20 | Mar 13 | Mar 8 | Mar 3 | Feb 27 | Feb 21 | Feb 12 |
| 16°F | Mar 13 | Mar 4 | Feb 27 | Feb 22 | Feb 18 | Feb 10 | Feb 2 | Jan 22 | Jan 9 |
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 | Aug 30 | Sep 5 | Sep 10 | Sep 14 | Sep 19 | Sep 22 | Sep 26 | Sep 29 | Oct 4 |
| 32°F | Sep 16 | Sep 24 | Sep 28 | Oct 1 | Oct 4 | Oct 6 | Oct 9 | Oct 13 | Oct 18 |
| 28°F | Oct 1 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 23 | Oct 27 | Nov 2 |
| 24°F | Oct 14 | Oct 19 | Oct 24 | Oct 28 | Oct 31 | Nov 3 | Nov 7 | Nov 13 | Nov 21 |
| 20°F | Oct 25 | Oct 30 | Nov 4 | Nov 9 | Nov 13 | Nov 19 | Nov 24 | Nov 29 | Dec 8 |
| 16°F | Nov 1 | Nov 10 | Nov 18 | Nov 24 | Nov 28 | Dec 3 | Dec 8 | Dec 16 | Dec 24 |
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 | 128 | 119 | 112 | 107 | 102 | 96 | 89 | 82 | 72 |
| 32°F | 164 | 156 | 151 | 146 | 143 | 138 | 132 | 125 | 115 |
| 28°F | 196 | 188 | 183 | 178 | 173 | 168 | 164 | 157 | 150 |
| 24°F | 240 | 229 | 221 | 215 | 210 | 205 | 198 | 190 | 180 |
| 20°F | 289 | 273 | 264 | 257 | 250 | 242 | 236 | 227 | 217 |
| 16°F | 331 | 316 | 306 | 298 | 288 | 279 | 270 | 262 | 249 |
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
- 6,219
- Cooling degree days, base 65°F
- 401
- Growing degree days, base 40°F
- 4,179
- Growing degree days, base 45°F
- 3,023
- Growing degree days, base 50°F
- 2,088
- Growing degree days, base 55°F
- 1,346
- Growing degree days, base 60°F
- 788
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,014 | 0 | 0 |
| February | 825 | 0 | 1 |
| March | 738 | 0 | 7 |
| April | 551 | 0 | 40 |
| May | 336 | 10 | 174 |
| June | 173 | 42 | 323 |
| July | 50 | 158 | 573 |
| August | 49 | 148 | 564 |
| September | 172 | 40 | 324 |
| October | 491 | 1 | 76 |
| November | 794 | 0 | 5 |
| December | 1,028 | 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 0.6 km from Moro. 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 USC00355734 (Moro). Public domain.