Talkeetna climate

Talkeetna Frost Dates and Growing Season

NOAA 1991-2020 normals for Talkeetna AP, 0.8 km from Talkeetna, elevation 350 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Talkeetna AP. 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 16 and the first fall freeze around September 16, a growing season of about 122 days.

Median at 36°F
last May 29, first September 3
Median at 32°F
last May 16, first September 16
Median at 28°F
last May 5, first September 28

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 10Jun 5Jun 2May 31May 29May 27May 25May 23May 19
32°FMay 28May 25May 22May 19May 16May 14May 12May 9May 6
28°FMay 17May 13May 10May 7May 5May 3May 1Apr 28Apr 24
24°FMay 5May 2Apr 30Apr 27Apr 24Apr 22Apr 19Apr 16Apr 12
20°FApr 27Apr 22Apr 19Apr 16Apr 14Apr 12Apr 9Apr 7Apr 4
16°FApr 21Apr 15Apr 12Apr 9Apr 7Apr 5Apr 3Apr 1Mar 29

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°FAug 23Aug 27Aug 30Sep 1Sep 3Sep 6Sep 9Sep 12Sep 17
32°FSep 1Sep 7Sep 10Sep 14Sep 16Sep 19Sep 22Sep 25Sep 29
28°FSep 13Sep 19Sep 22Sep 26Sep 28Sep 30Oct 3Oct 6Oct 12
24°FSep 24Sep 29Oct 1Oct 4Oct 6Oct 9Oct 12Oct 16Oct 21
20°FOct 1Oct 6Oct 10Oct 13Oct 16Oct 19Oct 21Oct 25Oct 29
16°FOct 8Oct 13Oct 17Oct 20Oct 23Oct 26Oct 29Nov 1Nov 5

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°F1121071031009793908680
32°F139133128125122119115110104
28°F163157153149146142139134127
24°F184178173169166162159154148
20°F200195190186182179175171165
16°F212207203199196193189184178

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
10,592
Cooling degree days, base 65°F
17
Growing degree days, base 40°F
2,192
Growing degree days, base 45°F
1,432
Growing degree days, base 50°F
808
Growing degree days, base 55°F
351
Growing degree days, base 60°F
101

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,59300
February1,29400
March1,28600
April86401
May536041
June2445216
July1639312
August2662205
September525033
October95601
November1,33300
December1,53100

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 0.8 km from Talkeetna. 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 USW00026528 (Talkeetna AP). Public domain.