Weston, WY frost dates
Last spring frostMay 23median date
First fall frostSep 18median date
Growing season118 daysfrost-free
Hardiness zone4bZone 4b
How Weston compares
- In 8 years out of 10, the last spring frost in Weston falls between May 11 and June 5, a 25-day window. The first fall frost falls between September 1 and October 1.
- The median last frost is 2 days later than the Wyoming median of May 21.
- Its 118-day growing season is longer than 32% of the 153 Wyoming places with a regular frost season (state median 125 days).
- The last frost is 15 days later than the zone 4b median of May 8. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4b chart.
- The weather station records an average of 188 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 11 |
| 50% (median) | May 23 |
| 10% (safe for tender plants) | June 5 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 1 |
| 50% (median) | September 18 |
| 90% (late) | October 1 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Weston, WY
Weston, WY frost dates — last frost May 23, first frost Sep 18, zone 4b. whenisthelastfrost.com
Crop
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Start indoors: Feb 28 to Mar 14Transplant outside: Apr 25 to May 9
Start indoors: Mar 14 to Mar 28Transplant outside: Jun 6 to Jun 20
Start indoors: Mar 14 to Mar 28Transplant outside: Jun 6 to Jun 20
Start indoors: Mar 28 to Apr 11Transplant outside: May 30 to Jun 13
Start indoors: Mar 28 to Apr 11Transplant outside: May 2 to May 16Sow outdoors: Apr 25 to May 30Plant for fall: Jul 24 to Aug 21
Start indoors: Mar 28 to Apr 11Transplant outside: Apr 25 to May 9Sow outdoors: Apr 25 to May 9Plant for fall: Jul 10 to Jul 31
Start indoors: Mar 28 to Apr 11Transplant outside: May 9 to May 23Plant for fall: Jun 12 to Jul 3
Start indoors: Mar 28 to Apr 11Transplant outside: May 2 to May 16Plant for fall: Jun 12 to Jul 3
Start indoors: Mar 28 to Apr 11Transplant outside: May 9 to May 23Plant for fall: Jun 12 to Jul 3
Start indoors: Apr 11 to Apr 25Transplant outside: Jun 13 to Jun 27Sow outdoors: Jun 13 to Jun 27
Start indoors: Apr 11 to Apr 25Transplant outside: May 30 to Jun 13
Sow outdoors: Apr 11 to May 2Plant for fall: Jun 26 to Jul 17
Sow outdoors: Apr 11 to May 2Plant for fall: Jul 24 to Aug 14
Sow outdoors: Apr 18 to May 30Plant for fall: Aug 7 to Aug 28
Start indoors: Apr 25 to May 2Transplant outside: Jun 6 to Jun 13Sow outdoors: May 30 to Jun 13Plant for fall: Jul 3 to Jul 17
Start indoors: Apr 25 to May 2Sow outdoors: May 30 to Jun 13Plant for fall: Jul 10 to Jul 24
Start indoors: Apr 25 to May 2Sow outdoors: May 30 to Jun 13
Start indoors: Apr 25 to May 2Transplant outside: Jun 6 to Jun 20
Sow outdoors: May 2 to May 30Plant for fall: Jun 26 to Jul 10
Sow outdoors: May 2 to May 30Plant for fall: Jul 10 to Jul 24
Sow outdoors: May 2 to May 23
Sow outdoors: May 9 to Jun 6Plant for fall: Jul 10 to Jul 24
Sow outdoors: May 9 to May 30Plant for fall: Jul 24 to Aug 14
Sow outdoors: May 30 to Jun 20
Sow outdoors: May 30 to Jun 13
Transplant outside: Jun 6 to Jun 27
Plant for fall: Sep 4 to Oct 9
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Weston, WY
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 28 – Mar 14 | Apr 25 – May 9 | — | — |
| Peppers | Mar 14 – Mar 28 | Jun 6 – Jun 20 | — | — |
| Eggplant | Mar 14 – Mar 28 | Jun 6 – Jun 20 | — | — |
| Tomatoes | Mar 28 – Apr 11 | May 30 – Jun 13 | — | — |
| Lettuce | Mar 28 – Apr 11 | May 2 – May 16 | Apr 25 – May 30 | Jul 24 – Aug 21 |
| Kale | Mar 28 – Apr 11 | Apr 25 – May 9 | Apr 25 – May 9 | Jul 10 – Jul 31 |
| Broccoli | Mar 28 – Apr 11 | May 9 – May 23 | — | Jun 12 – Jul 3 |
| Cabbage | Mar 28 – Apr 11 | May 2 – May 16 | — | Jun 12 – Jul 3 |
| Cauliflower | Mar 28 – Apr 11 | May 9 – May 23 | — | Jun 12 – Jul 3 |
| Okra | Apr 11 – Apr 25 | Jun 13 – Jun 27 | Jun 13 – Jun 27 | — |
| Basil | Apr 11 – Apr 25 | May 30 – Jun 13 | — | — |
| Peas | — | — | Apr 11 – May 2 | Jun 26 – Jul 17 |
| Spinach | — | — | Apr 11 – May 2 | Jul 24 – Aug 14 |
| Radishes | — | — | Apr 18 – May 30 | Aug 7 – Aug 28 |
| Cucumbers | Apr 25 – May 2 | Jun 6 – Jun 13 | May 30 – Jun 13 | Jul 3 – Jul 17 |
| Zucchini & Summer Squash | Apr 25 – May 2 | — | May 30 – Jun 13 | Jul 10 – Jul 24 |
| Winter Squash & Pumpkins | Apr 25 – May 2 | — | May 30 – Jun 13 | — |
| Melons & Watermelon | Apr 25 – May 2 | Jun 6 – Jun 20 | — | — |
| Carrots | — | — | May 2 – May 30 | Jun 26 – Jul 10 |
| Beets | — | — | May 2 – May 30 | Jul 10 – Jul 24 |
| Potatoes | — | — | May 2 – May 23 | — |
| Swiss Chard | — | — | May 9 – Jun 6 | Jul 10 – Jul 24 |
| Cilantro | — | — | May 9 – May 30 | Jul 24 – Aug 14 |
| Green Beans | — | — | May 30 – Jun 20 | — |
| Sweet Corn | — | — | May 30 – Jun 13 | — |
| Sweet Potatoes | — | Jun 6 – Jun 27 | — | — |
| Garlic | — | — | — | Sep 4 – Oct 9 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Weston 1 E, WY weather station, 15 km away (elevation 3,737 ft (1,139 m)).
Frost dates near Weston
- Recluse May 21 · Sep 23
- Rozet May 15 · Oct 1
- Gillette May 15 · Oct 1
- Moorcroft May 23 · Sep 20
- Hulett May 17 · Sep 23
- Devils Tower May 23 · Sep 20
- Arvada May 14 · Sep 30
- Leiter May 14 · Sep 30
- Alva May 17 · Sep 23
- Sundance May 21 · Sep 25
Frequently asked questions
When is the last frost in Weston, WY?
The median last spring frost in Weston, WY is May 23. There is still about a 10% chance of frost after June 5, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Weston, WY?
The median first fall frost is September 18, with about a 10% chance of frost before September 1.
How long is the growing season in Weston, WY?
About 118 days between the median last spring frost and first fall frost.
What planting zone is Weston, WY?
Weston, WY is in USDA hardiness zone 4b.