Refugio climate

Refugio Frost Dates and Growing Season

NOAA 1991-2020 normals for Refugio 2 Nw, 3.3 km from Refugio, elevation 45 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Refugio 2 Nw. 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 February 27 and the first fall freeze around December 2, a growing season of about 283 days.

Median at 36°F
last March 10, first November 21
Median at 32°F
last February 27, first December 2
Median at 28°F
last February 7, first December 18

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°FMar 31Mar 24Mar 18Mar 14Mar 10Mar 6Mar 2Feb 26Feb 17
32°FMar 19Mar 13Mar 7Mar 2Feb 27Feb 22Feb 15Feb 4Jan 26
28°FMar 9Mar 2Feb 24Feb 17Feb 7Jan 31Jan 21Jan 10Dec 29
24°FMar 4Feb 22Feb 10Feb 1Jan 22Jan 9Jan 3Dec 27Dec 16
20°FFeb 22Feb 6Jan 23Jan 12Jan 6Jan 2Dec 28Dec 20Dec 13
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.

Threshold10%20%30%40%50%60%70%80%90%
36°FNov 2Nov 7Nov 12Nov 17Nov 21Nov 25Nov 30Dec 4Dec 11
32°FNov 10Nov 17Nov 24Nov 29Dec 2Dec 6Dec 12Dec 22Jan 2
28°FNov 23Dec 1Dec 6Dec 11Dec 18Dec 25Jan 1Jan 9Feb 1
24°FDec 5Dec 11Dec 17Dec 24Jan 1Jan 5Jan 12Feb 1Feb 17
20°FDec 7Dec 17Dec 23Dec 31Jan 2Jan 5Jan 14Feb 1Feb 14
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.

Threshold10%20%30%40%50%60%70%80%90%
36°F288278270264258251245239229
32°F324308300292283276270262251
28°F365347338328316307298289277
24°F365365365365356347337324306
20°F365365365365365365365359343
16°F365365365365365365365365365

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
99% of years
28°F or colder
91% of years
24°F or colder
62% of years
20°F or colder
27% of years
16°F or colder
6% 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
1,061
Cooling degree days, base 65°F
3,308
Growing degree days, base 40°F
11,383
Growing degree days, base 45°F
9,588
Growing degree days, base 50°F
7,844
Growing degree days, base 55°F
6,197
Growing degree days, base 60°F
4,676

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January31021221
February20735273
March10497465
April25195620
May2384848
June0514964
July05911,056
August06071,073
September0468918
October18266713
November11894434
December27835260

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

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00417533 (Refugio 2 Nw). Public domain.