FrostDateByZip

Frost dates for 58718Berthold, ND

The average last spring frost in Berthold is May 11 and the average first fall frost is September 29, giving a typical growing season of about 138 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost
May 11

Safer after May 29 (1-in-10 risk)

Average first fall frost
Sep 29

Possible by Sep 13 (1-in-10 risk)

Growing season
138 days

Last frost typically in 196 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 6 · May 20 · Jun 12Sep 4 · Sep 20 · Oct 2122 days100%
Frost / freeze (32°F)Apr 28 · May 11 · May 29Sep 13 · Sep 29 · Oct 13138 days100%
Hard freeze (28°F)Apr 17 · May 2 · May 20Sep 21 · Oct 7 · Oct 23157 days100%

Planting calendar for Berthold

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 10 – Jun 16
TomatoesTransplant outdoorsMay 27 – Jun 9
PeppersStart seeds indoorsApr 10 – May 11
PeppersTransplant outdoorsJun 10 – Jul 11
EggplantStart seeds indoorsApr 27 – May 26
EggplantTransplant outdoorsJun 10 – Jul 11
CucumbersSow outdoorsJun 10 – Jun 19
Summer squashSow outdoorsMay 27 – Jul 11
Winter squash & pumpkinsSow outdoorsJun 10 – Jul 11
Snap beansSow outdoorsMay 27 – Jul 12
Sweet cornSow outdoorsMay 27 – Jun 9
Watermelon & cantaloupeSow outdoorsJun 10 – Jul 11
OkraSow outdoorsJun 3 – Jun 26
PeasSow outdoors (spring)Apr 10 – May 26
PotatoesPlant outdoors (spring)Apr 10 – Jun 10
OnionsStart seeds indoors (spring)Feb 27 – Mar 26
OnionsTransplant outdoors (spring)Apr 27 – May 26
BroccoliStart seeds indoors (spring)Mar 23 – Apr 26
BroccoliTransplant outdoors (spring)Apr 27 – May 26
BroccoliStart seeds indoors (fall)May 30 – Jun 9
BroccoliTransplant outdoors (fall)Jun 29 – Jul 10
CabbageStart seeds indoors (spring)Mar 13 – Apr 10
CabbageTransplant outdoors (spring)Apr 10 – May 11
CabbageStart seeds indoors (fall)May 20 – Jun 19
CabbageTransplant outdoors (fall)Jun 19 – Jul 20
Leaf lettuceSow outdoors (spring)Apr 10 – Jun 26
Leaf lettuceSow outdoors (fall)Jun 19 – Aug 5
SpinachSow outdoors (spring)Apr 3 – May 17
SpinachSow outdoors (fall)Jul 6 – Aug 10
RadishesSow outdoors (spring)Apr 10 – May 31
RadishesSow outdoors (fall)Jun 19 – Aug 20
KaleSow outdoors (spring)Apr 27 – May 17
KaleSow outdoors (fall)Jun 12 – Jul 20
CarrotsSow outdoors (spring)May 11 – Jun 26
CarrotsSow outdoors (fall)May 20 – Jul 5
GarlicPlant outdoors (fall)Sep 19 – Oct 20

Where these dates come from

ZIP code 58718 is matched to the NOAA station Foxholm 7 N, ND, 19 km away, at 1,675 ft elevation (346 ft lower than the ZIP code's center). Nearby stations for comparison:

StationElevationAvg last frostAvg first frost
Foxholm 7 N, ND (used)1,675 ftMay 11Sep 29
Minot Intl Ap, ND1,665 ftMay 10Oct 1
Minot Exp Stn, ND1,769 ftMay 13Sep 27
Kenmare 1 Wsw, ND1,810 ftMay 15Sep 23

Frost dates near Berthold

Frequently asked questions

When is the last frost in Berthold, ND?
For ZIP code 58718, the average last spring frost (32°F) is May 11, based on NOAA 1991-2020 climate normals for the Foxholm 7 N, ND weather station. There is a 1-in-10 chance of a frost after May 29.
When is the first frost in Berthold, ND?
The average first fall frost (32°F) is September 29. There is a 1-in-10 chance of frost by September 13, so tender plants are at risk from that point on.
How long is the growing season in 58718?
In half of years, the frost-free season (between the last and first 32°F frost) is at least 138 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.