Roberts climate

Roberts Frost Dates and Growing Season

NOAA 1991-2020 normals for Baldwin, 13.2 km from Roberts, elevation 1100 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Baldwin. 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 6 and the first fall freeze around October 2, a growing season of about 148 days.

Median at 36°F
last May 16, first September 24
Median at 32°F
last May 6, first October 2
Median at 28°F
last April 26, first October 12

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 29May 25May 21May 18May 16May 13May 10May 7May 3
32°FMay 21May 16May 12May 8May 6May 3Apr 30Apr 28Apr 21
28°FMay 12May 6May 2Apr 30Apr 26Apr 22Apr 19Apr 15Apr 9
24°FMay 1Apr 25Apr 21Apr 17Apr 14Apr 10Apr 7Apr 5Apr 1
20°FApr 19Apr 13Apr 9Apr 7Apr 5Apr 3Apr 1Mar 29Mar 21
16°FApr 11Apr 6Apr 4Apr 1Mar 31Mar 28Mar 23Mar 19Mar 14

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 10Sep 14Sep 18Sep 21Sep 24Sep 26Sep 29Oct 3Oct 6
32°FSep 18Sep 23Sep 26Sep 29Oct 2Oct 5Oct 7Oct 12Oct 17
28°FSep 26Oct 1Oct 5Oct 9Oct 12Oct 16Oct 20Oct 23Oct 28
24°FOct 9Oct 15Oct 19Oct 22Oct 24Oct 28Oct 31Nov 2Nov 8
20°FOct 20Oct 26Oct 29Nov 1Nov 2Nov 5Nov 8Nov 12Nov 16
16°FOct 31Nov 2Nov 5Nov 8Nov 11Nov 13Nov 17Nov 21Nov 25

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°F148143139134130126123118111
32°F168161156152148144140136128
28°F190184178173169165161154147
24°F211206200196192187182176170
20°F228222217213209205200196190
16°F246238233228224220216212205

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
8,528
Cooling degree days, base 65°F
401
Growing degree days, base 40°F
4,082
Growing degree days, base 45°F
3,103
Growing degree days, base 50°F
2,241
Growing degree days, base 55°F
1,494
Growing degree days, base 60°F
868

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,67200
February1,38900
March1,138010
April655145
May32016208
June6286474
July21150593
August43107528
September19640311
October591269
November99804
December1,44400

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 13.2 km from Roberts. 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 USC00470486 (Baldwin). Public domain.