Munds Park Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Mund's Park. 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 June 10 and the first fall freeze around September 27, a growing season of about 106 days.
- Median at 36°F
- last June 24, first September 17
- Median at 32°F
- last June 10, first September 27
- Median at 28°F
- last May 26, 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 | Jul 8 | Jul 2 | Jun 30 | Jun 28 | Jun 24 | Jun 21 | Jun 18 | Jun 14 | Jun 11 |
| 32°F | Jun 27 | Jun 21 | Jun 17 | Jun 14 | Jun 10 | Jun 8 | Jun 5 | Jun 2 | May 26 |
| 28°F | Jun 12 | Jun 6 | Jun 3 | May 31 | May 26 | May 21 | May 17 | May 12 | May 5 |
| 24°F | May 26 | May 17 | May 12 | May 7 | May 3 | Apr 30 | Apr 27 | Apr 23 | Apr 18 |
| 20°F | May 2 | Apr 27 | Apr 22 | Apr 19 | Apr 14 | Apr 11 | Apr 7 | Apr 3 | Mar 29 |
| 16°F | Apr 13 | Apr 7 | Apr 3 | Mar 30 | Mar 24 | Mar 18 | Mar 14 | Mar 8 | Mar 3 |
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 5 | Sep 8 | Sep 12 | Sep 14 | Sep 17 | Sep 19 | Sep 22 | Sep 24 | Sep 27 |
| 32°F | Sep 14 | Sep 19 | Sep 22 | Sep 25 | Sep 27 | Sep 29 | Oct 1 | Oct 4 | Oct 8 |
| 28°F | Sep 26 | Sep 30 | Oct 2 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 17 | Oct 22 |
| 24°F | Oct 6 | Oct 12 | Oct 15 | Oct 17 | Oct 20 | Oct 23 | Oct 27 | Nov 1 | Nov 4 |
| 20°F | Oct 17 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 16 |
| 16°F | Oct 27 | Nov 1 | Nov 6 | Nov 10 | Nov 14 | Nov 17 | Nov 21 | Nov 24 | Nov 30 |
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 | 100 | 95 | 91 | 86 | 83 | 80 | 74 | 69 | 62 |
| 32°F | 126 | 117 | 113 | 110 | 106 | 103 | 98 | 94 | 87 |
| 28°F | 157 | 150 | 143 | 138 | 133 | 129 | 125 | 119 | 113 |
| 24°F | 190 | 182 | 177 | 172 | 167 | 163 | 157 | 152 | 143 |
| 20°F | 221 | 212 | 208 | 203 | 198 | 194 | 189 | 183 | 174 |
| 16°F | 258 | 251 | 243 | 237 | 231 | 226 | 221 | 214 | 205 |
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
- 6,696
- Cooling degree days, base 65°F
- 139
- Growing degree days, base 40°F
- 3,622
- Growing degree days, base 45°F
- 2,561
- Growing degree days, base 50°F
- 1,689
- Growing degree days, base 55°F
- 997
- Growing degree days, base 60°F
- 474
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,048 | 0 | 0 |
| February | 895 | 0 | 0 |
| March | 839 | 0 | 1 |
| April | 647 | 0 | 12 |
| May | 434 | 0 | 97 |
| June | 177 | 12 | 291 |
| July | 37 | 72 | 501 |
| August | 43 | 49 | 471 |
| September | 197 | 5 | 262 |
| October | 518 | 0 | 52 |
| November | 800 | 0 | 3 |
| December | 1,063 | 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 1.1 km from Munds Park. 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 USC00025780 (Mund's Park). Public domain.