Gold Camp Frost Dates and Growing Season

NOAA 1991-2020 normals for Superior, 19.2 km from Gold Camp, elevation 2860 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Superior. 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 January 18 and the first fall freeze around December 28, a growing season of about 342 days.

Median at 36°F: last February 18, first December 11
Median at 32°F: last January 18, first December 28
Median at 28°F: last January 9, first January 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	Mar 31	Mar 14	Mar 4	Feb 25	Feb 18	Feb 9	Feb 1	Jan 21	Jan 8
32°F	Mar 1	Feb 15	Feb 3	Jan 26	Jan 18	Jan 10	Jan 4	Dec 31	Dec 19
28°F	Feb 10	Feb 1	Jan 23	Jan 13	Jan 9	Jan 6	Jan 3	Dec 31	Dec 22
24°F	–	–	–	–	–	–	–	–	–
20°F	–	–	–	–	–	–	–	–	–
16°F	–	–	–	–	–	–	–	–	–

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	Nov 24	Nov 29	Dec 4	Dec 8	Dec 11	Dec 15	Dec 20	Dec 25	Jan 4
32°F	Dec 1	Dec 10	Dec 15	Dec 22	Dec 28	Jan 1	Jan 8	Jan 19	Feb 1
28°F	Dec 14	Dec 27	Dec 31	Jan 3	Jan 7	Jan 10	Jan 19	Jan 29	Feb 5
24°F	–	–	–	–	–	–	–	–	–
20°F	–	–	–	–	–	–	–	–	–
16°F	–	–	–	–	–	–	–	–	–

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	334	322	311	301	292	283	274	262	250
32°F	365	365	359	350	342	334	326	313	294
28°F	365	365	365	365	365	365	365	360	345
24°F	365	365	365	365	365	365	365	365	365
20°F	365	365	365	365	365	365	365	365	365
16°F	365	365	365	365	365	365	365	365	365

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder: 99% of years
32°F or colder: 77% of years
28°F or colder: 26% of years
24°F or colder: 2% of years
20°F or colder: 0% of years
16°F or colder: 0% 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: 1,454
Cooling degree days, base 65°F: 3,383
Growing degree days, base 40°F: 11,058
Growing degree days, base 45°F: 9,263
Growing degree days, base 50°F: 7,546
Growing degree days, base 55°F: 5,976
Growing degree days, base 60°F: 4,585

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	369	2	140
February	270	5	178
March	186	43	336
April	72	118	500
May	11	332	786
June	1	603	1,053
July	0	714	1,179
August	0	676	1,141
September	0	533	982
October	22	287	730
November	150	67	378
December	375	3	141

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 19.2 km from Gold Camp. 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 USC00028348 (Superior). Public domain.