Salamanca climate

Salamanca Frost Dates and Growing Season

NOAA 1991-2020 normals for Salamanca 2, 0.9 km from Salamanca, elevation 1415 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Salamanca 2. 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 18 and the first fall freeze around October 1, a growing season of about 135 days.

Median at 36°F
last May 31, first September 20
Median at 32°F
last May 18, first October 1
Median at 28°F
last May 5, first October 11

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°FJun 15Jun 9Jun 5Jun 2May 31May 28May 25May 21May 15
32°FJun 1May 29May 26May 22May 18May 15May 11May 6May 2
28°FMay 23May 17May 13May 8May 5May 2Apr 29Apr 25Apr 20
24°FMay 11May 4May 1Apr 27Apr 24Apr 21Apr 17Apr 13Apr 7
20°FApr 27Apr 22Apr 18Apr 14Apr 11Apr 7Apr 4Apr 1Mar 26
16°FApr 15Apr 9Apr 5Apr 3Mar 31Mar 29Mar 25Mar 21Mar 17

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°FSep 5Sep 11Sep 15Sep 18Sep 20Sep 23Sep 25Sep 29Oct 2
32°FSep 19Sep 23Sep 26Sep 29Oct 1Oct 3Oct 5Oct 8Oct 12
28°FSep 30Oct 2Oct 5Oct 7Oct 11Oct 13Oct 16Oct 20Oct 25
24°FOct 8Oct 13Oct 17Oct 20Oct 23Oct 26Oct 29Nov 2Nov 6
20°FOct 20Oct 26Oct 30Nov 1Nov 5Nov 8Nov 11Nov 15Nov 20
16°FNov 1Nov 6Nov 10Nov 13Nov 16Nov 19Nov 24Nov 28Dec 4

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°F1311241181141111071029786
32°F156149143139135131127122116
28°F179171166161157153149143137
24°F204197191186181175171166158
20°F230222216211207203198193185
16°F252245239235231226221216209

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
7,308
Cooling degree days, base 65°F
338
Growing degree days, base 40°F
4,096
Growing degree days, base 45°F
3,053
Growing degree days, base 50°F
2,151
Growing degree days, base 55°F
1,387
Growing degree days, base 60°F
774

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,31001
February1,15800
March1,02608
April626251
May31722216
June10372421
July34125556
August4991507
September18625301
October537275
November821013
December1,14403

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 0.9 km from Salamanca. 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 USC00307400 (Salamanca 2). Public domain.