FrostDateByZip

Frost dates for 55318Chaska, MN

The average last spring frost in Chaska is April 30 and the average first fall frost is October 9, giving a typical growing season of about 160 days. Dates are based on NOAA 1991-2020 climate normals.

Average last spring frost
Apr 30

Safer after May 15 (1-in-10 risk)

Average first fall frost
Oct 9

Possible by Sep 25 (1-in-10 risk)

Growing season
160 days

Last frost typically in 181 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)Apr 27 · May 9 · May 24Sep 17 · Sep 30 · Oct 11142 days100%
Frost / freeze (32°F)Apr 15 · Apr 30 · May 15Sep 25 · Oct 9 · Oct 21160 days100%
Hard freeze (28°F)Apr 4 · Apr 19 · May 4Oct 4 · Oct 19 · Oct 31180 days100%

Planting calendar for Chaska

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 indoorsMar 30 – Jun 5
TomatoesTransplant outdoorsMay 16 – Jun 19
PeppersStart seeds indoorsMar 30 – Apr 30
PeppersTransplant outdoorsMay 30 – Jun 30
EggplantStart seeds indoorsApr 16 – May 15
EggplantTransplant outdoorsMay 30 – Jun 30
CucumbersSow outdoorsMay 30 – Jun 29
Summer squashSow outdoorsMay 16 – Jun 30
Winter squash & pumpkinsSow outdoorsMay 30 – Jun 30
Snap beansSow outdoorsMay 16 – Jul 22
Sweet cornSow outdoorsMay 16 – Jun 19
Watermelon & cantaloupeSow outdoorsMay 30 – Jun 30
OkraSow outdoorsMay 23 – Jun 15
PeasSow outdoors (spring)Mar 30 – May 15
PotatoesPlant outdoors (spring)Mar 30 – May 30
OnionsStart seeds indoors (spring)Feb 16 – Mar 15
OnionsTransplant outdoors (spring)Apr 16 – May 15
BroccoliStart seeds indoors (spring)Mar 12 – Apr 15
BroccoliTransplant outdoors (spring)Apr 16 – May 15
BroccoliStart seeds indoors (fall)Jun 9 – Jun 19
BroccoliTransplant outdoors (fall)Jul 9 – Jul 20
CabbageStart seeds indoors (spring)Mar 2 – Mar 30
CabbageTransplant outdoors (spring)Mar 30 – Apr 30
CabbageStart seeds indoors (fall)May 30 – Jun 29
CabbageTransplant outdoors (fall)Jun 29 – Jul 30
Leaf lettuceSow outdoors (spring)Mar 30 – Jun 15
Leaf lettuceSow outdoors (fall)Jun 29 – Aug 15
SpinachSow outdoors (spring)Mar 23 – May 6
SpinachSow outdoors (fall)Jul 16 – Aug 20
RadishesSow outdoors (spring)Mar 30 – May 20
RadishesSow outdoors (fall)Jun 29 – Aug 30
KaleSow outdoors (spring)Apr 16 – May 6
KaleSow outdoors (fall)Jun 22 – Jul 30
CarrotsSow outdoors (spring)Apr 30 – Jun 15
CarrotsSow outdoors (fall)May 30 – Jul 15
GarlicPlant outdoors (fall)Sep 29 – Oct 30

Where these dates come from

ZIP code 55318 is matched to the NOAA station Chanhassen Wsfo, MN, 6 km away, at 946 ft elevation (47 ft higher than the ZIP code's center). Nearby stations for comparison:

StationElevationAvg last frostAvg first frost
Chanhassen Wsfo, MN (used)946 ftApr 30Oct 9
Chaska 2Nw, MN923 ftMay 5Oct 5
Mpls Flying Cloud Ap, MN907 ftApr 23Oct 14
Jordan 1Ssw, MN900 ftMay 2Oct 5

Frost dates near Chaska

Frequently asked questions

When is the last frost in Chaska, MN?
For ZIP code 55318, the average last spring frost (32°F) is April 30, based on NOAA 1991-2020 climate normals for the Chanhassen Wsfo, MN weather station. There is a 1-in-10 chance of a frost after May 15.
When is the first frost in Chaska, MN?
The average first fall frost (32°F) is October 9. There is a 1-in-10 chance of frost by September 25, so tender plants are at risk from that point on.
How long is the growing season in 55318?
In half of years, the frost-free season (between the last and first 32°F frost) is at least 160 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.