Dawson climate

Dawson Frost Dates and Growing Season

NOAA 1991-2020 normals for Navarro Mills Dam, 7.9 km from Dawson, elevation 454 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Navarro Mills Dam. 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 March 13 and the first fall freeze around November 14, a growing season of about 250 days.

Median at 36°F
last March 26, first November 4
Median at 32°F
last March 13, first November 14
Median at 28°F
last February 27, first November 29

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°FApr 15Apr 9Apr 4Mar 31Mar 26Mar 22Mar 17Mar 11Mar 3
32°FApr 3Mar 28Mar 21Mar 16Mar 13Mar 8Mar 3Feb 27Feb 19
28°FMar 19Mar 14Mar 9Mar 3Feb 27Feb 22Feb 16Feb 7Jan 28
24°FMar 10Mar 1Feb 23Feb 15Feb 7Jan 31Jan 28Jan 20Jan 10
20°FFeb 28Feb 17Feb 5Jan 31Jan 26Jan 18Jan 11Jan 2Dec 23
16°FFeb 19Feb 7Feb 1Jan 24Jan 16Jan 10Jan 4Dec 30Dec 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°FOct 20Oct 25Oct 29Nov 1Nov 4Nov 7Nov 11Nov 16Nov 23
32°FOct 30Nov 3Nov 7Nov 10Nov 14Nov 19Nov 23Nov 30Dec 6
28°FNov 6Nov 12Nov 18Nov 23Nov 29Dec 3Dec 8Dec 15Dec 26
24°FNov 17Nov 26Dec 1Dec 6Dec 13Dec 22Dec 29Jan 4Jan 16
20°FDec 1Dec 9Dec 17Dec 26Jan 1Jan 6Jan 12Jan 20Feb 2
16°FDec 11Dec 22Dec 30Jan 3Jan 8Jan 13Jan 23Feb 1Feb 15

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°F252242234229223218213208198
32°F278269263256250244237230221
28°F311299290283276269262254243
24°F342333324315308300292283271
20°F365365357349342334326316303
16°F365365365365365365364352335

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
98% of years
20°F or colder
77% of years
16°F or colder
34% 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
2,291
Cooling degree days, base 65°F
2,635
Growing degree days, base 40°F
9,576
Growing degree days, base 45°F
7,907
Growing degree days, base 50°F
6,362
Growing degree days, base 55°F
4,960
Growing degree days, base 60°F
3,715

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January590367
February4197113
March26428269
April9990445
May13267719
June0473922
July06001,065
August06041,069
September5393838
October81140528
November29225234
December529592

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 7.9 km from Dawson. 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 USC00416210 (Navarro Mills Dam). Public domain.