Juniata Frost Dates and Growing Season
Frost and the growing season
NOAA's 1991-2020 freeze probabilities for Hastings Muni AP. 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 April 22 and the first fall freeze around October 16, a growing season of about 176 days.
- Median at 36°F
- last May 1, first October 7
- Median at 32°F
- last April 22, first October 16
- Median at 28°F
- last April 12, first October 25
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 | May 14 | May 9 | May 6 | May 4 | May 1 | Apr 29 | Apr 27 | Apr 23 | Apr 19 |
| 32°F | May 5 | May 1 | Apr 28 | Apr 25 | Apr 22 | Apr 19 | Apr 16 | Apr 12 | Apr 8 |
| 28°F | Apr 26 | Apr 22 | Apr 19 | Apr 16 | Apr 12 | Apr 9 | Apr 6 | Apr 2 | Mar 29 |
| 24°F | Apr 18 | Apr 13 | Apr 8 | Apr 5 | Apr 2 | Mar 31 | Mar 27 | Mar 23 | Mar 17 |
| 20°F | Apr 8 | Apr 2 | Mar 31 | Mar 28 | Mar 24 | Mar 20 | Mar 16 | Mar 12 | Mar 5 |
| 16°F | Apr 1 | Mar 26 | Mar 21 | Mar 17 | Mar 13 | Mar 10 | Mar 5 | Mar 2 | Feb 26 |
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 25 | Sep 29 | Oct 2 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 20 |
| 32°F | Oct 2 | Oct 7 | Oct 11 | Oct 13 | Oct 16 | Oct 19 | Oct 21 | Oct 24 | Oct 28 |
| 28°F | Oct 10 | Oct 16 | Oct 19 | Oct 23 | Oct 25 | Oct 28 | Oct 30 | Nov 3 | Nov 7 |
| 24°F | Oct 20 | Oct 25 | Oct 29 | Oct 31 | Nov 3 | Nov 6 | Nov 8 | Nov 12 | Nov 18 |
| 20°F | Oct 27 | Nov 1 | Nov 4 | Nov 8 | Nov 11 | Nov 15 | Nov 18 | Nov 22 | Nov 28 |
| 16°F | Nov 2 | Nov 8 | Nov 13 | Nov 16 | Nov 20 | Nov 23 | Nov 27 | Dec 1 | Dec 8 |
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 | 175 | 169 | 165 | 161 | 158 | 154 | 150 | 146 | 139 |
| 32°F | 195 | 188 | 183 | 179 | 176 | 172 | 168 | 164 | 157 |
| 28°F | 216 | 209 | 204 | 200 | 196 | 192 | 187 | 182 | 174 |
| 24°F | 234 | 227 | 222 | 217 | 214 | 210 | 206 | 200 | 193 |
| 20°F | 255 | 246 | 241 | 236 | 231 | 226 | 221 | 216 | 207 |
| 16°F | 274 | 265 | 259 | 254 | 249 | 245 | 239 | 233 | 224 |
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
- 5,871
- Cooling degree days, base 65°F
- 1,136
- Growing degree days, base 40°F
- 5,787
- Growing degree days, base 45°F
- 4,592
- Growing degree days, base 50°F
- 3,535
- Growing degree days, base 55°F
- 2,605
- Growing degree days, base 60°F
- 1,807
Growing degree days by month, base 50°F
Heating and cooling by month
| Month | Heating DD | Cooling DD | Growing DD 50 |
|---|---|---|---|
| January | 1,197 | 0 | 0 |
| February | 978 | 0 | 4 |
| March | 748 | 1 | 41 |
| April | 427 | 7 | 132 |
| May | 167 | 66 | 375 |
| June | 16 | 247 | 681 |
| July | 2 | 373 | 837 |
| August | 4 | 298 | 759 |
| September | 83 | 127 | 496 |
| October | 382 | 16 | 181 |
| November | 759 | 0 | 28 |
| December | 1,108 | 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 6.8 km from Juniata. 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 USW00094949 (Hastings Muni AP). Public domain.