Lynn climate

Lynn Frost Dates and Growing Season

NOAA 1991-2020 normals for Winchester Airport 3 E, 13.6 km from Lynn, elevation 1110 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Winchester Airport 3 E. 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 20 and the first fall freeze around October 21, a growing season of about 183 days.

Median at 36°F
last May 1, first October 10
Median at 32°F
last April 20, first October 21
Median at 28°F
last April 9, first November 1

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 7May 4May 1Apr 28Apr 25Apr 22Apr 18
32°FMay 5Apr 30Apr 27Apr 23Apr 20Apr 18Apr 14Apr 11Apr 6
28°FApr 25Apr 19Apr 16Apr 12Apr 9Apr 6Apr 3Apr 1Mar 26
24°FApr 13Apr 6Apr 3Apr 1Mar 30Mar 27Mar 24Mar 20Mar 16
20°FApr 3Mar 30Mar 27Mar 23Mar 20Mar 17Mar 14Mar 11Mar 5
16°FMar 26Mar 20Mar 17Mar 14Mar 11Mar 8Mar 4Feb 28Feb 20

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 27Oct 1Oct 4Oct 7Oct 10Oct 13Oct 15Oct 18Oct 22
32°FOct 7Oct 12Oct 15Oct 18Oct 21Oct 23Oct 26Oct 29Nov 1
28°FOct 19Oct 24Oct 27Oct 30Nov 1Nov 3Nov 5Nov 10Nov 15
24°FOct 30Nov 2Nov 5Nov 8Nov 11Nov 15Nov 19Nov 23Nov 30
20°FNov 7Nov 12Nov 16Nov 20Nov 24Nov 28Dec 1Dec 6Dec 14
16°FNov 15Nov 21Nov 27Dec 1Dec 5Dec 9Dec 14Dec 20Dec 26

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°F180174169165162158154149140
32°F202196191187183179174169161
28°F223217212208204200196191183
24°F248241235231226222218213206
20°F272263257252247243238233225
16°F295286279274269264259252245

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
5,983
Cooling degree days, base 65°F
830
Growing degree days, base 40°F
5,407
Growing degree days, base 45°F
4,231
Growing degree days, base 50°F
3,183
Growing degree days, base 55°F
2,262
Growing degree days, base 60°F
1,475

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,22402
February1,02702
March822129
April4479131
May17566367
June31184603
July4258719
August11203657
September9394455
October37214180
November719134
December1,05704

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 13.6 km from Lynn. 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 USC00129678 (Winchester Airport 3 E). Public domain.