Frost dates for 82214Guernsey, WY
The average last spring frost in Guernsey is May 11 and the average first fall frost is October 3, giving a typical growing season of about 144 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 11
- Average first fall frost
- Oct 3
- Growing season
- 144 days
Safer after May 25 (1-in-10 risk)
Possible by Sep 19 (1-in-10 risk)
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.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | May 10 · May 22 · Jun 5 | Sep 9 · Sep 24 · Oct 6 | 124 days | 100% |
| Frost / freeze (32°F) | Apr 29 · May 11 · May 25 | Sep 19 · Oct 3 · Oct 15 | 144 days | 100% |
| Hard freeze (28°F) | Apr 16 · Apr 30 · May 13 | Sep 28 · Oct 13 · Oct 25 | 164 days | 100% |
Planting calendar for Guernsey
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.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Apr 10 – Jun 16 |
| Tomatoes | Transplant outdoors | May 27 – Jun 13 |
| Peppers | Start seeds indoors | Apr 10 – May 11 |
| Peppers | Transplant outdoors | Jun 10 – Jul 11 |
| Eggplant | Start seeds indoors | Apr 27 – May 26 |
| Eggplant | Transplant outdoors | Jun 10 – Jul 11 |
| Cucumbers | Sow outdoors | Jun 10 – Jun 23 |
| Summer squash | Sow outdoors | May 27 – Jul 11 |
| Winter squash & pumpkins | Sow outdoors | Jun 10 – Jul 11 |
| Snap beans | Sow outdoors | May 27 – Jul 16 |
| Sweet corn | Sow outdoors | May 27 – Jun 13 |
| Watermelon & cantaloupe | Sow outdoors | Jun 10 – Jul 11 |
| Okra | Sow outdoors | Jun 3 – Jun 26 |
| Peas | Sow outdoors (spring) | Apr 10 – May 26 |
| Potatoes | Plant outdoors (spring) | Apr 10 – Jun 10 |
| Onions | Start seeds indoors (spring) | Feb 27 – Mar 26 |
| Onions | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (spring) | Mar 23 – Apr 26 |
| Broccoli | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (fall) | Jun 3 – Jun 13 |
| Broccoli | Transplant outdoors (fall) | Jul 3 – Jul 14 |
| Cabbage | Start seeds indoors (spring) | Mar 13 – Apr 10 |
| Cabbage | Transplant outdoors (spring) | Apr 10 – May 11 |
| Cabbage | Start seeds indoors (fall) | May 24 – Jun 23 |
| Cabbage | Transplant outdoors (fall) | Jun 23 – Jul 24 |
| Leaf lettuce | Sow outdoors (spring) | Apr 10 – Jun 26 |
| Leaf lettuce | Sow outdoors (fall) | Jun 23 – Aug 9 |
| Spinach | Sow outdoors (spring) | Apr 3 – May 17 |
| Spinach | Sow outdoors (fall) | Jul 10 – Aug 14 |
| Radishes | Sow outdoors (spring) | Apr 10 – May 31 |
| Radishes | Sow outdoors (fall) | Jun 23 – Aug 24 |
| Kale | Sow outdoors (spring) | Apr 27 – May 17 |
| Kale | Sow outdoors (fall) | Jun 16 – Jul 24 |
| Carrots | Sow outdoors (spring) | May 11 – Jun 26 |
| Carrots | Sow outdoors (fall) | May 24 – Jul 9 |
| Garlic | Plant outdoors (fall) | Sep 23 – Oct 24 |
Where these dates come from
ZIP code 82214 is matched to the NOAA station Guernsey Dam #2, WY, 2.9 km away, at 4,355 ft elevation (24 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Guernsey Dam #2, WY (used) | 4,355 ft | May 11 | Oct 3 |
| Guernsey 2Nw, WY | 4,480 ft | May 7 | Oct 6 |
| Whalen Dam Usbr, WY | 4,294 ft | May 7 | Oct 3 |
| Old Ft Laramie, WY | 4,250 ft | May 14 | Sep 26 |
Frost dates near Guernsey
- Hartville, WY 82215 · last May 7, first Oct 6
- Fort Laramie, WY 82212 · last May 14, first Sep 26
- Wheatland, WY 82201 · last May 19, first Sep 22
- Jay Em, WY 82219 · last May 17, first Sep 28
- Glendo, WY 82213 · last May 9, first Oct 5
- Lingle, WY 82223 · last May 11, first Sep 29
- Veteran, WY 82243 · last May 15, first Sep 27
- Yoder, WY 82244 · last May 15, first Sep 27
Frequently asked questions
- When is the last frost in Guernsey, WY?
- For ZIP code 82214, the average last spring frost (32°F) is May 11, based on NOAA 1991-2020 climate normals for the Guernsey Dam #2, WY weather station. There is a 1-in-10 chance of a frost after May 25.
- When is the first frost in Guernsey, WY?
- The average first fall frost (32°F) is October 3. There is a 1-in-10 chance of frost by September 19, so tender plants are at risk from that point on.
- How long is the growing season in 82214?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 144 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.