FrostDateByZip

Frost dates for 04668Princeton, ME

The average last spring frost in Princeton is May 4 and the average first fall frost is October 10, giving a typical growing season of about 157 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost
May 4

Safer after May 18 (1-in-10 risk)

Average first fall frost
Oct 10

Possible by Oct 1 (1-in-10 risk)

Growing season
157 days

Last frost typically in 184 days

Frost risk by date

NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.

Spring dates: chance of a frost AFTER the date. Fall dates: chance of a frost BEFORE the date.
TemperatureLast spring: 90% / 50% / 10% chanceFirst fall: 10% / 50% / 90% chanceGrowing season (50%)Years with at least one
Light frost (36°F)May 3 · May 17 · Jun 1Sep 20 · Oct 1 · Oct 11135 days100%
Frost / freeze (32°F)Apr 24 · May 4 · May 18Oct 1 · Oct 10 · Oct 23157 days100%
Hard freeze (28°F)Apr 10 · Apr 24 · May 6Oct 9 · Oct 24 · Nov 6182 days100%

Planting calendar for Princeton

Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.

CropTaskWindow
TomatoesStart seeds indoorsApr 3 – Jun 9
TomatoesTransplant outdoorsMay 20 – Jun 20
PeppersStart seeds indoorsApr 3 – May 4
PeppersTransplant outdoorsJun 3 – Jul 4
EggplantStart seeds indoorsApr 20 – May 19
EggplantTransplant outdoorsJun 3 – Jul 4
CucumbersSow outdoorsJun 3 – Jun 30
Summer squashSow outdoorsMay 20 – Jul 4
Winter squash & pumpkinsSow outdoorsJun 3 – Jul 4
Snap beansSow outdoorsMay 20 – Jul 23
Sweet cornSow outdoorsMay 20 – Jun 20
Watermelon & cantaloupeSow outdoorsJun 3 – Jul 4
OkraSow outdoorsMay 27 – Jun 19
PeasSow outdoors (spring)Apr 3 – May 19
PotatoesPlant outdoors (spring)Apr 3 – Jun 3
OnionsStart seeds indoors (spring)Feb 20 – Mar 19
OnionsTransplant outdoors (spring)Apr 20 – May 19
BroccoliStart seeds indoors (spring)Mar 16 – Apr 19
BroccoliTransplant outdoors (spring)Apr 20 – May 19
BroccoliStart seeds indoors (fall)Jun 10 – Jun 20
BroccoliTransplant outdoors (fall)Jul 10 – Jul 21
CabbageStart seeds indoors (spring)Mar 6 – Apr 3
CabbageTransplant outdoors (spring)Apr 3 – May 4
CabbageStart seeds indoors (fall)May 31 – Jun 30
CabbageTransplant outdoors (fall)Jun 30 – Jul 31
Leaf lettuceSow outdoors (spring)Apr 3 – Jun 19
Leaf lettuceSow outdoors (fall)Jun 30 – Aug 16
SpinachSow outdoors (spring)Mar 27 – May 10
SpinachSow outdoors (fall)Jul 17 – Aug 21
RadishesSow outdoors (spring)Apr 3 – May 24
RadishesSow outdoors (fall)Jun 30 – Aug 31
KaleSow outdoors (spring)Apr 20 – May 10
KaleSow outdoors (fall)Jun 23 – Jul 31
CarrotsSow outdoors (spring)May 4 – Jun 19
CarrotsSow outdoors (fall)May 31 – Jul 16
GarlicPlant outdoors (fall)Sep 30 – Oct 31

Where these dates come from

ZIP code 04668 is matched to the NOAA station Grand Lake Stream, ME, 14.2 km away, at 290 ft elevation (87 ft higher than the ZIP code's center). Nearby stations for comparison:

StationElevationAvg last frostAvg first frost
Grand Lake Stream, ME (used)290 ftMay 4Oct 10
Woodland, ME123 ftApr 21Oct 26
Topsfield 2, ME620 ftMay 6Oct 8
Wesley, ME410 ftMay 2Oct 15

Frost dates near Princeton

Frequently asked questions

When is the last frost in Princeton, ME?
For ZIP code 04668, the average last spring frost (32°F) is May 4, based on NOAA 1991-2020 climate normals for the Grand Lake Stream, ME weather station. There is a 1-in-10 chance of a frost after May 18.
When is the first frost in Princeton, ME?
The average first fall frost (32°F) is October 10. There is a 1-in-10 chance of frost by October 1, so tender plants are at risk from that point on.
How long is the growing season in 04668?
In half of years, the frost-free season (between the last and first 32°F frost) is at least 157 days long.
Are these frost dates a forecast?
No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.