Bridgeton climate

Bridgeton Frost Dates and Growing Season

NOAA 1991-2020 normals for Portland Intl AP, 5.5 km from Bridgeton, elevation 19 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Portland Intl 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 March 13 and the first fall freeze around November 19, a growing season of about 247 days.

Median at 36°F
last April 6, first November 2
Median at 32°F
last March 13, first November 19
Median at 28°F
last February 16, first December 5

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

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

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°F234224218214210204199193184
32°F277266260253247242236229219
28°F337323313306298291283274263
24°F365365364353342334325316306
20°F365365365365365365359344331
16°F365365365365365365365365360

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
98% of years
24°F or colder
69% of years
20°F or colder
30% of years
16°F or colder
11% 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
4,104
Cooling degree days, base 65°F
508
Growing degree days, base 40°F
5,658
Growing degree days, base 45°F
4,104
Growing degree days, base 50°F
2,832
Growing degree days, base 55°F
1,833
Growing degree days, base 60°F
1,063

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January71805
February58408
March519037
April3672112
May19621292
June8056426
July10171626
August7181639
September6173462
October2974187
November539032
December72705

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 5.5 km from Bridgeton. 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 USW00024229 (Portland Intl AP). Public domain.