Republic climate

Republic Frost Dates and Growing Season

NOAA 1991-2020 normals for Republic, 0.2 km from Republic, elevation 2555 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Republic. 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 May 30 and the first fall freeze around September 10, a growing season of about 102 days.

Median at 32°F
last May 30, first September 10
Median at 28°F
last May 12, first September 24

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.

Threshold10%20%30%40%50%60%70%80%90%
36°F–––––––––
32°FJun 17Jun 11Jun 5Jun 1May 30May 27May 23May 17May 11
28°FMay 28May 22May 17May 14May 12May 8May 5Apr 30Apr 27
24°FMay 12May 7May 3Apr 30Apr 27Apr 24Apr 20Apr 17Apr 11
20°FApr 28Apr 21Apr 15Apr 9Apr 6Apr 3Mar 31Mar 27Mar 19
16°FApr 4Mar 30Mar 26Mar 20Mar 17Mar 14Mar 11Mar 7Mar 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.

Threshold10%20%30%40%50%60%70%80%90%
36°F–––––––––
32°FAug 28Sep 2Sep 5Sep 7Sep 10Sep 13Sep 16Sep 20Sep 25
28°FSep 11Sep 15Sep 18Sep 21Sep 24Sep 26Sep 29Oct 1Oct 5
24°FSep 23Sep 28Oct 1Oct 2Oct 5Oct 7Oct 11Oct 14Oct 19
20°FOct 1Oct 6Oct 10Oct 14Oct 18Oct 22Oct 25Oct 30Nov 5
16°FOct 12Oct 19Oct 24Oct 29Oct 31Nov 3Nov 7Nov 13Nov 20

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.

Threshold10%20%30%40%50%60%70%80%90%
36°F878175716661565042
32°F12511711210710297938779
28°F154147143138135130127121115
24°F185178172167163158154149142
20°F221213206201195189184178171
16°F255245239234229224218210202

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
7,866
Cooling degree days, base 65°F
167
Growing degree days, base 40°F
3,291
Growing degree days, base 45°F
2,339
Growing degree days, base 50°F
1,547
Growing degree days, base 55°F
910
Growing degree days, base 60°F
449

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,28300
February1,03700
March89101
April638017
May3912127
June21913250
July6978475
August7866453
September2788203
October677022
November1,00500
December1,29900

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 0.2 km from Republic. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00456974 (Republic). Public domain.