Banner, WY frost dates
How Banner compares
- In 8 years out of 10, the last spring frost in Banner falls between May 10 and June 9, a 30-day window. The first fall frost falls between September 8 and October 7.
- The median last frost is 3 days later than the Wyoming median of May 21.
- Its 122-day growing season is longer than 41% of the 153 Wyoming places with a regular frost season (state median 125 days).
- The last frost is 21 days later than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 193 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 10 |
| 50% (median) | May 24 |
| 10% (safe for tender plants) | June 9 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 8 |
| 50% (median) | September 23 |
| 90% (late) | October 7 |
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 Banner, WY
Banner, WY frost dates — last frost May 24, first frost Sep 23, zone 5a. whenisthelastfrost.com
When to plant vegetables in Banner, WY
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 1 – Mar 15 | Apr 26 – May 10 | — | — |
| Peppers | Mar 15 – Mar 29 | Jun 7 – Jun 21 | — | — |
| Eggplant | Mar 15 – Mar 29 | Jun 7 – Jun 21 | — | — |
| Tomatoes | Mar 29 – Apr 12 | May 31 – Jun 14 | — | — |
| Lettuce | Mar 29 – Apr 12 | May 3 – May 17 | Apr 26 – May 31 | Jul 29 – Aug 26 |
| Kale | Mar 29 – Apr 12 | Apr 26 – May 10 | Apr 26 – May 10 | Jul 15 – Aug 5 |
| Broccoli | Mar 29 – Apr 12 | May 10 – May 24 | — | Jun 17 – Jul 8 |
| Cabbage | Mar 29 – Apr 12 | May 3 – May 17 | — | Jun 17 – Jul 8 |
| Cauliflower | Mar 29 – Apr 12 | May 10 – May 24 | — | Jun 17 – Jul 8 |
| Okra | Apr 12 – Apr 26 | Jun 14 – Jun 28 | Jun 14 – Jun 28 | — |
| Basil | Apr 12 – Apr 26 | May 31 – Jun 14 | — | — |
| Peas | — | — | Apr 12 – May 3 | Jul 1 – Jul 22 |
| Spinach | — | — | Apr 12 – May 3 | Jul 29 – Aug 19 |
| Radishes | — | — | Apr 19 – May 31 | Aug 12 – Sep 2 |
| Cucumbers | Apr 26 – May 3 | Jun 7 – Jun 14 | May 31 – Jun 14 | Jul 8 – Jul 22 |
| Zucchini & Summer Squash | Apr 26 – May 3 | — | May 31 – Jun 14 | Jul 15 – Jul 29 |
| Winter Squash & Pumpkins | Apr 26 – May 3 | — | May 31 – Jun 14 | — |
| Melons & Watermelon | Apr 26 – May 3 | Jun 7 – Jun 21 | — | — |
| Carrots | — | — | May 3 – May 31 | Jul 1 – Jul 15 |
| Beets | — | — | May 3 – May 31 | Jul 15 – Jul 29 |
| Potatoes | — | — | May 3 – May 24 | — |
| Swiss Chard | — | — | May 10 – Jun 7 | Jul 15 – Jul 29 |
| Cilantro | — | — | May 10 – May 31 | Jul 29 – Aug 19 |
| Green Beans | — | — | May 31 – Jun 21 | Jul 8 – Jul 22 |
| Sweet Corn | — | — | May 31 – Jun 14 | — |
| Sweet Potatoes | — | Jun 7 – Jun 28 | — | — |
| Garlic | — | — | — | Sep 9 – Oct 14 |
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 Story, WY weather station, 9 km away (elevation 5,167 ft (1,575 m)).
Frost dates near Banner
- Story May 24 · Sep 23
- Saddlestring May 24 · Sep 23
- Wyarno May 18 · Sep 24
- Big Horn May 17 · Sep 28
- Sheridan May 21 · Sep 23
- Clearmont May 24 · Sep 16
- Buffalo May 24 · Sep 21
- Wolf May 24 · Sep 18
- Leiter May 14 · Sep 30
- Ranchester May 24 · Sep 18
Frequently asked questions
When is the last frost in Banner, WY?
The median last spring frost in Banner, WY is May 24. There is still about a 10% chance of frost after June 9, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Banner, WY?
The median first fall frost is September 23, with about a 10% chance of frost before September 8.
How long is the growing season in Banner, WY?
About 122 days between the median last spring frost and first fall frost.
What planting zone is Banner, WY?
Banner, WY is in USDA hardiness zone 5a.