Hugo Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Hugo 1 Nw. 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 10 and the first fall freeze around October 2, a growing season of about 143 days.
- Median at 36°F
- last May 22, first September 24
- Median at 32°F
- last May 10, first October 2
- Median at 28°F
- last May 1, first October 10
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 | Jun 1 | May 28 | May 25 | May 22 | May 19 | May 16 | May 13 | May 10 |
| 32°F | May 25 | May 19 | May 15 | May 13 | May 10 | May 8 | May 6 | May 3 | Apr 30 |
| 28°F | May 13 | May 9 | May 6 | May 4 | May 1 | Apr 30 | Apr 27 | Apr 23 | Apr 18 |
| 24°F | May 3 | Apr 30 | Apr 27 | Apr 23 | Apr 20 | Apr 18 | Apr 15 | Apr 12 | Apr 6 |
| 20°F | Apr 23 | Apr 19 | Apr 15 | Apr 12 | Apr 9 | Apr 6 | Apr 2 | Mar 31 | Mar 23 |
| 16°F | Apr 15 | Apr 9 | Apr 5 | Apr 2 | Mar 31 | Mar 26 | Mar 21 | Mar 15 | Mar 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 | Sep 11 | Sep 16 | Sep 19 | Sep 22 | Sep 24 | Sep 27 | Sep 29 | Oct 1 | Oct 5 |
| 32°F | Sep 21 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 4 | Oct 6 | Oct 9 | Oct 13 |
| 28°F | Sep 28 | Oct 1 | Oct 5 | Oct 7 | Oct 10 | Oct 12 | Oct 14 | Oct 17 | Oct 21 |
| 24°F | Oct 5 | Oct 9 | Oct 12 | Oct 15 | Oct 17 | Oct 20 | Oct 22 | Oct 25 | Oct 30 |
| 20°F | Oct 11 | Oct 16 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Oct 31 | Nov 3 | Nov 8 |
| 16°F | Oct 16 | Oct 21 | Oct 25 | Oct 29 | Nov 1 | Nov 4 | Nov 8 | Nov 13 | Nov 19 |
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 | 141 | 136 | 132 | 128 | 124 | 120 | 116 | 112 | 105 |
| 32°F | 160 | 154 | 150 | 146 | 143 | 139 | 136 | 131 | 123 |
| 28°F | 178 | 172 | 168 | 165 | 162 | 158 | 155 | 150 | 145 |
| 24°F | 197 | 190 | 185 | 182 | 178 | 174 | 171 | 167 | 161 |
| 20°F | 220 | 212 | 206 | 201 | 197 | 193 | 189 | 184 | 177 |
| 16°F | 242 | 234 | 228 | 222 | 217 | 211 | 207 | 200 | 192 |
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
- 6,349
- Cooling degree days, base 65°F
- 605
- Growing degree days, base 40°F
- 4,759
- Growing degree days, base 45°F
- 3,626
- Growing degree days, base 50°F
- 2,652
- Growing degree days, base 55°F
- 1,828
- Growing degree days, base 60°F
- 1,146
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,116 | 0 | 1 |
| February | 959 | 0 | 1 |
| March | 797 | 0 | 17 |
| April | 560 | 0 | 57 |
| May | 280 | 15 | 237 |
| June | 56 | 109 | 503 |
| July | 7 | 242 | 700 |
| August | 13 | 185 | 637 |
| September | 133 | 53 | 381 |
| October | 492 | 1 | 105 |
| November | 825 | 0 | 13 |
| December | 1,111 | 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 1.9 km from Hugo. 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 USC00054172 (Hugo 1 Nw). Public domain.