Adams County Frost Dates and Growing Season

NOAA 1991-2020 normals for New Meadows RS, 15.6 km from Adams County, elevation 3862 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for New Meadows RS. 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 1, first September 9

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 24	Jun 15	Jun 10	Jun 5	Jun 1	May 29	May 24	May 19	May 12
24°F	May 31	May 23	May 17	May 14	May 11	May 7	May 5	May 2	Apr 28
20°F	May 11	May 5	May 2	Apr 29	Apr 25	Apr 20	Apr 15	Apr 9	Apr 2
16°F	Apr 28	Apr 19	Apr 10	Apr 4	Mar 31	Mar 27	Mar 22	Mar 17	Mar 12

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 25	Sep 1	Sep 4	Sep 7	Sep 9	Sep 12	Sep 15	Sep 19	Sep 24
24°F	Sep 6	Sep 11	Sep 15	Sep 19	Sep 22	Sep 25	Sep 28	Oct 1	Oct 6
20°F	Sep 17	Sep 24	Sep 27	Oct 1	Oct 3	Oct 6	Oct 12	Oct 17	Oct 24
16°F	Sep 30	Oct 4	Oct 10	Oct 15	Oct 19	Oct 24	Oct 28	Nov 1	Nov 10

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	52	44	38	34	30	27	24	21	17
32°F	86	79	73	67	62	56	50	44	35
28°F	123	113	107	101	96	89	84	78	69
24°F	153	147	142	137	133	128	123	117	107
20°F	190	180	174	168	162	157	151	146	138
16°F	228	219	212	206	200	194	188	179	168

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: 8,687
Cooling degree days, base 65°F: 108
Growing degree days, base 40°F: 2,854
Growing degree days, base 45°F: 1,981
Growing degree days, base 50°F: 1,278
Growing degree days, base 55°F: 730
Growing degree days, base 60°F: 337

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	1,404	0	0
February	1,144	0	0
March	994	0	0
April	723	0	9
May	509	0	68
June	288	8	195
July	88	58	437
August	111	38	395
September	339	3	157
October	711	0	18
November	1,032	0	0
December	1,344	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 15.6 km from Adams County. 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 USC00106388 (New Meadows RS). Public domain.