Sidney climate

Sidney Frost Dates and Growing Season

NOAA 1991-2020 normals for Sidney Muni AP, 4.7 km from Sidney, elevation 4309 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sidney Muni 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 15 and the first fall freeze around September 30, a growing season of about 135 days.

Median at 36°F
last May 26, first September 21
Median at 32°F
last May 15, first September 30
Median at 28°F
last May 5, first October 9

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

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 7Sep 12Sep 15Sep 19Sep 21Sep 24Sep 26Sep 29Oct 2
32°FSep 15Sep 21Sep 25Sep 27Sep 30Oct 3Oct 5Oct 8Oct 12
28°FSep 26Oct 1Oct 4Oct 7Oct 9Oct 12Oct 14Oct 17Oct 21
24°FOct 5Oct 10Oct 13Oct 16Oct 18Oct 20Oct 23Oct 25Oct 29
20°FOct 12Oct 17Oct 20Oct 23Oct 26Oct 28Oct 31Nov 3Nov 7
16°FOct 19Oct 24Oct 28Nov 1Nov 3Nov 6Nov 10Nov 14Nov 18

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°F13412812412011611310910396
32°F152147143139135131128123116
28°F172166162158154151148143137
24°F191185181177174170165161156
20°F213207201197193190186181173
16°F236230223218214209204197190

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
6,680
Cooling degree days, base 65°F
692
Growing degree days, base 40°F
4,691
Growing degree days, base 45°F
3,598
Growing degree days, base 50°F
2,660
Growing degree days, base 55°F
1,873
Growing degree days, base 60°F
1,219

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,16100
February99801
March826014
April591048
May31915208
June69114496
July6275734
August16220669
September14465383
October526396
November86309
December1,16100

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 4.7 km from Sidney. 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 USW00024030 (Sidney Muni AP). Public domain.