Ludlow climate

Ludlow Frost Dates and Growing Season

NOAA 1991-2020 normals for Cavendish, 8.3 km from Ludlow, elevation 842 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Cavendish. 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 29, a growing season of about 136 days.

Median at 36°F
last May 28, first September 19
Median at 32°F
last May 16, first September 29
Median at 28°F
last May 2, first October 7

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 3May 31May 28May 25May 23May 19May 14
32°FMay 31May 25May 21May 18May 16May 13May 9May 6May 1
28°FMay 15May 11May 8May 5May 2Apr 30Apr 28Apr 25Apr 22
24°FMay 3Apr 28Apr 25Apr 22Apr 20Apr 18Apr 16Apr 12Apr 8
20°FApr 20Apr 16Apr 13Apr 10Apr 8Apr 6Apr 4Apr 2Mar 31
16°FApr 10Apr 6Apr 4Apr 3Apr 1Mar 31Mar 28Mar 24Mar 19

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 5Sep 10Sep 13Sep 16Sep 19Sep 21Sep 25Sep 27Oct 1
32°FSep 16Sep 20Sep 24Sep 26Sep 29Oct 1Oct 3Oct 6Oct 11
28°FSep 26Sep 30Oct 2Oct 5Oct 7Oct 10Oct 14Oct 18Oct 25
24°FOct 4Oct 9Oct 13Oct 17Oct 20Oct 24Oct 27Nov 1Nov 5
20°FOct 17Oct 23Oct 27Oct 31Nov 3Nov 5Nov 9Nov 13Nov 19
16°FNov 1Nov 5Nov 10Nov 13Nov 16Nov 19Nov 23Nov 27Dec 1

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°F13112512011611210910510095
32°F153148143140136131128123116
28°F176170165161158154150145138
24°F202195190187183179174169161
20°F227221216212208204200195189
16°F247239235231227224220215210

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
7,818
Cooling degree days, base 65°F
363
Growing degree days, base 40°F
3,939
Growing degree days, base 45°F
2,965
Growing degree days, base 50°F
2,114
Growing degree days, base 55°F
1,388
Growing degree days, base 60°F
797

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,43500
February1,24200
March1,10502
April685130
May32712188
June9970423
July21145589
August40105530
September20029291
October565156
November87305
December1,22600

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 8.3 km from Ludlow. 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 USC00431243 (Cavendish). Public domain.