Madras climate

Madras Frost Dates and Growing Season

NOAA 1991-2020 normals for Madras 2 N, 3.5 km from Madras, elevation 2443 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Madras 2 N. 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 19 and the first fall freeze around October 4, a growing season of about 136 days.

Median at 36°F
last June 10, first September 19
Median at 32°F
last May 19, first October 4
Median at 28°F
last May 2, first October 17

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 28Jun 22Jun 17Jun 14Jun 10Jun 5Jun 1May 28May 21
32°FJun 7May 31May 28May 23May 19May 14May 11May 7May 2
28°FMay 20May 13May 8May 6May 2Apr 30Apr 28Apr 25Apr 20
24°FMay 5Apr 30Apr 26Apr 22Apr 18Apr 15Apr 11Apr 6Mar 30
20°FApr 18Apr 9Apr 2Mar 29Mar 23Mar 15Mar 9Feb 28Feb 19
16°FMar 23Mar 11Mar 2Feb 27Feb 22Feb 16Feb 9Jan 31Jan 15

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 2Sep 8Sep 12Sep 16Sep 19Sep 22Sep 25Sep 29Oct 4
32°FSep 20Sep 24Sep 28Oct 1Oct 4Oct 6Oct 9Oct 13Oct 18
28°FOct 1Oct 6Oct 10Oct 14Oct 17Oct 21Oct 24Oct 27Nov 1
24°FOct 16Oct 22Oct 25Oct 28Oct 30Nov 2Nov 7Nov 12Nov 20
20°FOct 26Oct 31Nov 5Nov 10Nov 14Nov 19Nov 23Nov 27Dec 3
16°FNov 1Nov 11Nov 16Nov 22Nov 26Dec 1Dec 5Dec 12Dec 22

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°F12411611010510094888273
32°F159152146141136131125119110
28°F187181177172167163159153146
24°F223214207201196191187181173
20°F273261251244238231224215205
16°F321307298290281273264254240

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
6,185
Cooling degree days, base 65°F
367
Growing degree days, base 40°F
4,150
Growing degree days, base 45°F
2,990
Growing degree days, base 50°F
2,059
Growing degree days, base 55°F
1,325
Growing degree days, base 60°F
765

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January97201
February82601
March73809
April573034
May35211166
June16735322
July44146567
August43136558
September17437320
October495174
November78607
December1,01500

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 3.5 km from Madras. 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 USC00355142 (Madras 2 N). Public domain.