Buffalo, WY frost dates
Last spring frostMay 24median date
First fall frostSep 21median date
Growing season120 daysfrost-free
Hardiness zone5aZone 5a
How Buffalo compares
- In 8 years out of 10, the last spring frost in Buffalo falls between May 12 and June 9, a 28-day window. The first fall frost falls between September 7 and October 3.
- The median last frost is 3 days later than the Wyoming median of May 21.
- Its 120-day growing season is longer than 33% 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 184 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 12 |
| 50% (median) | May 24 |
| 10% (safe for tender plants) | June 9 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 7 |
| 50% (median) | September 21 |
| 90% (late) | October 3 |
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 Buffalo, WY
Buffalo, WY frost dates — last frost May 24, first frost Sep 21, zone 5a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Mar 1 to Mar 15Transplant outside: Apr 26 to May 10
Start indoors: Mar 15 to Mar 29Transplant outside: Jun 7 to Jun 21
Start indoors: Mar 15 to Mar 29Transplant outside: Jun 7 to Jun 21
Start indoors: Mar 29 to Apr 12Transplant outside: May 31 to Jun 14
Start indoors: Mar 29 to Apr 12Transplant outside: May 3 to May 17Sow outdoors: Apr 26 to May 31Plant for fall: Jul 27 to Aug 24
Start indoors: Mar 29 to Apr 12Transplant outside: Apr 26 to May 10Sow outdoors: Apr 26 to May 10Plant for fall: Jul 13 to Aug 3
Start indoors: Mar 29 to Apr 12Transplant outside: May 10 to May 24Plant for fall: Jun 15 to Jul 6
Start indoors: Mar 29 to Apr 12Transplant outside: May 3 to May 17Plant for fall: Jun 15 to Jul 6
Start indoors: Mar 29 to Apr 12Transplant outside: May 10 to May 24Plant for fall: Jun 15 to Jul 6
Start indoors: Apr 12 to Apr 26Transplant outside: Jun 14 to Jun 28Sow outdoors: Jun 14 to Jun 28
Start indoors: Apr 12 to Apr 26Transplant outside: May 31 to Jun 14
Sow outdoors: Apr 12 to May 3Plant for fall: Jun 29 to Jul 20
Sow outdoors: Apr 12 to May 3Plant for fall: Jul 27 to Aug 17
Sow outdoors: Apr 19 to May 31Plant for fall: Aug 10 to Aug 31
Start indoors: Apr 26 to May 3Transplant outside: Jun 7 to Jun 14Sow outdoors: May 31 to Jun 14Plant for fall: Jul 6 to Jul 20
Start indoors: Apr 26 to May 3Sow outdoors: May 31 to Jun 14Plant for fall: Jul 13 to Jul 27
Start indoors: Apr 26 to May 3Sow outdoors: May 31 to Jun 14
Start indoors: Apr 26 to May 3Transplant outside: Jun 7 to Jun 21
Sow outdoors: May 3 to May 31Plant for fall: Jun 29 to Jul 13
Sow outdoors: May 3 to May 31Plant for fall: Jul 13 to Jul 27
Sow outdoors: May 3 to May 24
Sow outdoors: May 10 to Jun 7Plant for fall: Jul 13 to Jul 27
Sow outdoors: May 10 to May 31Plant for fall: Jul 27 to Aug 17
Sow outdoors: May 31 to Jun 21Plant for fall: Jul 6 to Jul 20
Sow outdoors: May 31 to Jun 14
Transplant outside: Jun 7 to Jun 28
Plant for fall: Sep 7 to Oct 12
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Buffalo, 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 27 – Aug 24 |
| Kale | Mar 29 – Apr 12 | Apr 26 – May 10 | Apr 26 – May 10 | Jul 13 – Aug 3 |
| Broccoli | Mar 29 – Apr 12 | May 10 – May 24 | — | Jun 15 – Jul 6 |
| Cabbage | Mar 29 – Apr 12 | May 3 – May 17 | — | Jun 15 – Jul 6 |
| Cauliflower | Mar 29 – Apr 12 | May 10 – May 24 | — | Jun 15 – Jul 6 |
| 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 | Jun 29 – Jul 20 |
| Spinach | — | — | Apr 12 – May 3 | Jul 27 – Aug 17 |
| Radishes | — | — | Apr 19 – May 31 | Aug 10 – Aug 31 |
| Cucumbers | Apr 26 – May 3 | Jun 7 – Jun 14 | May 31 – Jun 14 | Jul 6 – Jul 20 |
| Zucchini & Summer Squash | Apr 26 – May 3 | — | May 31 – Jun 14 | Jul 13 – Jul 27 |
| 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 | Jun 29 – Jul 13 |
| Beets | — | — | May 3 – May 31 | Jul 13 – Jul 27 |
| Potatoes | — | — | May 3 – May 24 | — |
| Swiss Chard | — | — | May 10 – Jun 7 | Jul 13 – Jul 27 |
| Cilantro | — | — | May 10 – May 31 | Jul 27 – Aug 17 |
| Green Beans | — | — | May 31 – Jun 21 | Jul 6 – Jul 20 |
| Sweet Corn | — | — | May 31 – Jun 14 | — |
| Sweet Potatoes | — | Jun 7 – Jun 28 | — | — |
| Garlic | — | — | — | Sep 7 – Oct 12 |
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 Buffalo, WY weather station, about 1 km away (elevation 4,639 ft (1,414 m)).
Frost dates near Buffalo
- Saddlestring May 24 · Sep 23
- Banner May 24 · Sep 23
- Story May 24 · Sep 23
- Clearmont May 24 · Sep 16
- Big Horn May 17 · Sep 28
- Wyarno May 18 · Sep 24
- Sheridan May 21 · Sep 23
- Leiter May 14 · Sep 30
- Arvada May 14 · Sep 30
- Wolf May 24 · Sep 18
Frequently asked questions
When is the last frost in Buffalo, WY?
The median last spring frost in Buffalo, 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 Buffalo, WY?
The median first fall frost is September 21, with about a 10% chance of frost before September 7.
How long is the growing season in Buffalo, WY?
About 120 days between the median last spring frost and first fall frost.
What planting zone is Buffalo, WY?
Buffalo, WY is in USDA hardiness zone 5a.