Negaunee Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Marquette. 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 22 and the first fall freeze around September 29, a growing season of about 129 days.
- Median at 36°F
- last June 3, first September 14
- Median at 32°F
- last May 22, first September 29
- Median at 28°F
- last May 8, 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 19 | Jun 14 | Jun 9 | Jun 5 | Jun 3 | Jun 1 | May 30 | May 27 | May 22 |
| 32°F | Jun 4 | Jun 1 | May 29 | May 26 | May 22 | May 19 | May 15 | May 11 | May 6 |
| 28°F | May 23 | May 18 | May 14 | May 11 | May 8 | May 5 | May 2 | Apr 29 | Apr 26 |
| 24°F | May 11 | May 7 | May 4 | May 1 | Apr 29 | Apr 26 | Apr 23 | Apr 19 | Apr 14 |
| 20°F | May 2 | Apr 28 | Apr 25 | Apr 22 | Apr 19 | Apr 16 | Apr 14 | Apr 10 | Apr 6 |
| 16°F | Apr 24 | Apr 19 | Apr 16 | Apr 13 | Apr 10 | Apr 8 | Apr 5 | Apr 3 | Mar 31 |
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 27 | Sep 2 | Sep 6 | Sep 11 | Sep 14 | Sep 18 | Sep 21 | Sep 25 | Oct 1 |
| 32°F | Sep 11 | Sep 18 | Sep 22 | Sep 25 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 12 |
| 28°F | Sep 24 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 17 | Oct 21 | Oct 26 |
| 24°F | Oct 7 | Oct 13 | Oct 17 | Oct 20 | Oct 24 | Oct 27 | Oct 31 | Nov 3 | Nov 7 |
| 20°F | Oct 24 | Oct 29 | Nov 1 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 14 | Nov 18 |
| 16°F | Nov 2 | Nov 5 | Nov 9 | Nov 12 | Nov 15 | Nov 18 | Nov 21 | Nov 24 | Dec 1 |
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 | 123 | 116 | 111 | 108 | 102 | 98 | 93 | 87 | 77 |
| 32°F | 149 | 142 | 137 | 133 | 129 | 125 | 121 | 116 | 108 |
| 28°F | 175 | 168 | 163 | 159 | 155 | 151 | 146 | 140 | 133 |
| 24°F | 199 | 191 | 187 | 183 | 178 | 174 | 169 | 164 | 155 |
| 20°F | 219 | 212 | 206 | 203 | 198 | 194 | 190 | 185 | 179 |
| 16°F | 236 | 229 | 224 | 220 | 216 | 212 | 208 | 203 | 197 |
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
- 9,218
- Cooling degree days, base 65°F
- 237
- Growing degree days, base 40°F
- 3,270
- Growing degree days, base 45°F
- 2,407
- Growing degree days, base 50°F
- 1,658
- Growing degree days, base 55°F
- 1,031
- Growing degree days, base 60°F
- 553
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,570 | 0 | 0 |
| February | 1,376 | 0 | 0 |
| March | 1,240 | 0 | 3 |
| April | 846 | 0 | 17 |
| May | 457 | 12 | 136 |
| June | 174 | 47 | 332 |
| July | 82 | 90 | 473 |
| August | 105 | 63 | 424 |
| September | 285 | 24 | 225 |
| October | 669 | 1 | 46 |
| November | 1,026 | 0 | 4 |
| December | 1,387 | 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 6 km from Negaunee. 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 USW00094850 (Marquette). Public domain.