Saint Albans climate

Saint Albans Frost Dates and Growing Season

NOAA 1991-2020 normals for Saint Albans, 0.4 km from Saint Albans, elevation 646 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Saint Albans. 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 April 18 and the first fall freeze around October 26, a growing season of about 189 days.

Median at 36°F
last April 30, first October 17
Median at 32°F
last April 18, first October 26
Median at 28°F
last April 4, first November 5

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°FMay 16May 10May 6May 3Apr 30Apr 27Apr 23Apr 19Apr 15
32°FMay 6Apr 30Apr 26Apr 22Apr 18Apr 15Apr 11Apr 7Apr 2
28°FApr 21Apr 15Apr 10Apr 7Apr 4Apr 2Mar 31Mar 26Mar 20
24°FApr 8Apr 3Mar 31Mar 28Mar 24Mar 20Mar 16Mar 11Mar 3
20°FMar 29Mar 23Mar 19Mar 15Mar 11Mar 7Mar 2Feb 26Feb 18
16°FMar 18Mar 11Mar 6Mar 1Feb 27Feb 22Feb 16Feb 9Feb 2

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°FOct 4Oct 7Oct 11Oct 14Oct 17Oct 19Oct 22Oct 25Oct 28
32°FOct 12Oct 16Oct 20Oct 23Oct 26Oct 29Nov 1Nov 3Nov 6
28°FOct 23Oct 28Oct 31Nov 1Nov 5Nov 7Nov 10Nov 13Nov 19
24°FNov 1Nov 6Nov 10Nov 13Nov 15Nov 19Nov 23Nov 29Dec 5
20°FNov 11Nov 16Nov 21Nov 25Nov 30Dec 2Dec 7Dec 13Dec 22
16°FNov 21Nov 30Dec 5Dec 11Dec 17Dec 22Dec 27Jan 1Jan 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.

Threshold10%20%30%40%50%60%70%80%90%
36°F188182176171167163159153146
32°F210202198193189184179174166
28°F234227222216212208204199191
24°F263254248242238231227221213
20°F293285278271265259253247238
16°F323311305299292287279272261

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
4,892
Cooling degree days, base 65°F
1,038
Growing degree days, base 40°F
6,100
Growing degree days, base 45°F
4,789
Growing degree days, base 50°F
3,639
Growing degree days, base 55°F
2,636
Growing degree days, base 60°F
1,768

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,01208
February837012
March670255
April32913195
May12479425
June11195635
July1320784
August2282745
September52130528
October33017201
November634039
December891011

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 0.4 km from Saint Albans. 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 USC00467852 (Saint Albans). Public domain.