Hillcrest climate

Hillcrest Frost Dates and Growing Season

NOAA 1991-2020 normals for Alvin, 3.9 km from Hillcrest, elevation 28 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Alvin. 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 14 and the first fall freeze around December 5, a growing season of about 298 days.

Median at 36°F
last March 5, first November 23
Median at 32°F
last February 14, first December 5
Median at 28°F
last January 25, first December 30

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 27Mar 18Mar 14Mar 9Mar 5Feb 28Feb 24Feb 17Feb 4
32°FMar 13Mar 6Feb 28Feb 23Feb 14Feb 5Jan 31Jan 24Jan 15
28°FMar 2Feb 19Feb 7Jan 31Jan 25Jan 20Jan 13Jan 4Dec 23
24°FFeb 16Feb 1Jan 25Jan 19Jan 14Jan 8Jan 3Dec 27Dec 15
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.

Threshold10%20%30%40%50%60%70%80%90%
36°FNov 5Nov 10Nov 15Nov 19Nov 23Nov 27Dec 1Dec 6Dec 15
32°FNov 14Nov 21Nov 26Dec 1Dec 5Dec 10Dec 18Dec 31Jan 8
28°FNov 27Dec 3Dec 11Dec 20Dec 30Jan 3Jan 8Jan 16Feb 2
24°FDec 8Dec 15Dec 25Jan 1Jan 4Jan 8Jan 14Jan 21Feb 1
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.

Threshold10%20%30%40%50%60%70%80%90%
36°F298285277271264259252245238
32°F335324312304298291281273261
28°F365363352343336329319306294
24°F365365365365365365356345334
20°F365365365365365365365365365
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
84% of years
24°F or colder
42% of years
20°F or colder
10% 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
1,273
Cooling degree days, base 65°F
2,868
Growing degree days, base 40°F
10,733
Growing degree days, base 45°F
8,945
Growing degree days, base 50°F
7,224
Growing degree days, base 55°F
5,620
Growing degree days, base 60°F
4,162

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January3699167
February23921227
March12167419
April37148562
May2346809
June0469919
July05411,006
August05441,009
September1434883
October25211651
November15161369
December32917203

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 3.9 km from Hillcrest. 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 USC00410204 (Alvin). Public domain.