Last frost date in Gillette, WY
In Gillette, the last spring frost comes around May 15 in an average year. Wait until May 27 if you want 90% odds of no more frost. The first fall frost usually arrives about October 1, which leaves 136 frost-free days. An early freeze before September 15 happens one year in ten.
- Safe after (10% risk)
- May 27
- Average first frost
- Oct 1
- Frost-free season
- 136 days
- Hard freeze (28°F) ends
- May 2
Frost likely Sat night, low 30°F
National Weather Service forecast, updated Oct 22, 12:57 UTC
- ThuOct 2253°
- FriOct 2334°possible frost
- SatOct 2430°frost
- SunOct 2530°frost
- MonOct 2629°frost
- TueOct 2732°frost
- WedOct 2832°frost
Planting calendar for Gillette
Windows count forward or back from the average frost dates above. Click a crop for dates across Wyoming.
TomatoesMay 22–Jun 5
PumpkinsMay 29–Jun 12
SunflowersMay 15–Jun 5
CucumbersMay 29–Jun 5
CornMay 22–Jun 5
Sweet potatoesJun 5–Jun 19
WatermelonMay 29–Jun 12
Green beansMay 22–Jun 12
ZucchiniMay 22–Jun 5
OkraJun 5–Jun 19
PeppersMay 29–Jun 12
BasilMay 22–Jun 5
Butternut squashMay 22–Jun 5
CantaloupeMay 29–Jun 12
EggplantMay 29–Jun 12
PotatoesApr 17–May 1
OnionsApr 3–Apr 24
CarrotsApr 24–May 29
LettuceMay 1–May 22
BroccoliApr 17–May 1
BeetsApr 17–May 29
PeasApr 3–Apr 17
CabbageApr 17–May 1
RadishesApr 10–May 22
Brussels sproutsMay 1–May 15
SpinachApr 3–Apr 24
CilantroMay 1–May 22
KaleApr 17–May 1
Collard greensApr 17–May 1
TurnipsApr 17–May 1
DillMay 15–May 29
CeleryMay 22–May 29
CauliflowerMay 1–May 15
LeeksMay 1–May 15
Swiss chardMay 1–May 29
ParsleyMay 1–May 22
Tulip bulbsSep 17–Oct 22
GarlicSep 10–Oct 15
Daffodil bulbsSep 3–Oct 15
StrawberriesApr 17–May 1
AsparagusApr 17–May 1Frost probabilities
| Threshold | Spring, 90% chance later | Spring, 50% | Spring, 10% | Fall, 10% chance earlier | Fall, 50% | Fall, 90% |
|---|---|---|---|---|---|---|
| Light frost, 32°F | May 1 | May 15 | May 27 | Sep 15 | Oct 1 | Oct 14 |
| Hard freeze, 28°F | Apr 18 | May 2 | May 15 | Sep 26 | Oct 10 | Oct 23 |
Read the spring 10% column as the date after which only one year in ten still gets frost. That is the safer date for tomatoes, peppers and basil.
Where these numbers come from
NOAA station Gillette 4SE (USC00483855) sits 2.5 miles from the center of Gillette at 4,640 feet. Its averages cover 1991 to 2020. Low spots, valleys and open fields can keep getting frost a week or two after the station stops; city centers and lakeshores usually get less of it.
Questions
When is the last frost in Gillette, WY?
The average last frost date in Gillette is May 15, based on NOAA 1991–2020 climate normals. There is a 10% chance of frost after May 27.
When is the first frost in Gillette?
The first frost in fall usually comes around October 1. One year in ten it arrives before September 15.
How long is the growing season in Gillette?
About 136 days between the average last and first frost.
When should I plant tomatoes in Gillette?
Plant tomato seedlings outside from May 22 to June 5. Start seeds indoors six to eight weeks earlier.
Nearby in Wyoming
- SheridanMay 21
- CasperMay 10
- LaramieJun 7
- CheyenneMay 14
- Rock SpringsMay 24