Spring Creek Frost Dates and Growing Season

NOAA 1991-2020 normals for Lamoille 2N, 8.7 km from Spring Creek, elevation 5750 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lamoille 2N. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

NOAA does not state freeze dates for this station.

Median at 28°F: last June 2, first September 6

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	–	–	–	–	–	–	–	–	–
32°F	–	–	–	–	–	–	–	–	–
28°F	Jun 21	Jun 13	Jun 8	Jun 5	Jun 2	May 29	May 25	May 20	May 15
24°F	May 29	May 23	May 19	May 16	May 13	May 10	May 7	May 3	Apr 30
20°F	May 16	May 10	May 7	May 3	May 1	Apr 29	Apr 26	Apr 22	Apr 18
16°F	May 4	Apr 30	Apr 25	Apr 21	Apr 17	Apr 14	Apr 11	Apr 8	Apr 4

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	–	–	–	–	–	–	–	–	–
32°F	–	–	–	–	–	–	–	–	–
28°F	Aug 23	Aug 29	Sep 1	Sep 4	Sep 6	Sep 9	Sep 12	Sep 17	Sep 22
24°F	Sep 3	Sep 7	Sep 11	Sep 15	Sep 18	Sep 20	Sep 23	Sep 27	Oct 3
20°F	Sep 13	Sep 18	Sep 23	Sep 27	Sep 29	Oct 2	Oct 5	Oct 9	Oct 15
16°F	Sep 25	Sep 30	Oct 4	Oct 7	Oct 11	Oct 14	Oct 18	Oct 21	Oct 28

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	54	46	41	37	33	30	26	23	19
32°F	87	81	74	69	63	58	53	46	37
28°F	121	112	108	103	97	93	88	82	72
24°F	146	140	136	131	127	123	119	113	105
20°F	170	164	158	154	150	144	140	135	128
16°F	199	190	184	179	174	169	164	156	148

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: 8,491
Cooling degree days, base 65°F: 65
Growing degree days, base 40°F: 2,867
Growing degree days, base 45°F: 1,974
Growing degree days, base 50°F: 1,252
Growing degree days, base 55°F: 680
Growing degree days, base 60°F: 276

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	1,313	0	0
February	1,109	0	0
March	974	0	0
April	763	0	7
May	529	0	67
June	266	5	212
July	78	38	425
August	122	21	366
September	350	2	152
October	694	0	22
November	1,010	0	1
December	1,285	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 8.7 km from Spring Creek. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00264391 (Lamoille 2N). Public domain.