Frost dates for 82931Evanston, WY
The average last spring frost in Evanston is June 12 and the average first fall frost is September 12, giving a typical growing season of about 90 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 12
- Average first fall frost
- Sep 12
- Growing season
- 90 days
Safer after Jul 2 (1-in-10 risk)
Possible by Aug 26 (1-in-10 risk)
Last frost typically in 228 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) | — | — | 63 days | 100% |
| Frost / freeze (32°F) | May 26 · Jun 12 · Jul 2 | Aug 26 · Sep 12 · Sep 25 | 90 days | 100% |
| Hard freeze (28°F) | May 5 · May 24 · Jun 14 | Sep 7 · Sep 24 · Oct 9 | 121 days | 100% |
Planting calendar for Evanston
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 | May 12 – Jul 18 |
| Tomatoes | Transplant outdoors | Jun 28 – May 23 |
| Peppers | Start seeds indoors | May 12 – Jun 12 |
| Peppers | Transplant outdoors | Jul 12 – Aug 12 |
| Eggplant | Start seeds indoors | May 29 – Jun 27 |
| Eggplant | Transplant outdoors | Jul 12 – Aug 12 |
| Cucumbers | Sow outdoors | Jul 12 – Jun 2 |
| Summer squash | Sow outdoors | Jun 28 – Aug 12 |
| Winter squash & pumpkins | Sow outdoors | Jul 12 – Aug 12 |
| Snap beans | Sow outdoors | Jun 28 – Jun 25 |
| Sweet corn | Sow outdoors | Jun 28 – May 23 |
| Watermelon & cantaloupe | Sow outdoors | Jul 12 – Aug 12 |
| Okra | Sow outdoors | Jul 5 – Jul 28 |
| Peas | Sow outdoors (spring) | May 12 – Jun 27 |
| Potatoes | Plant outdoors (spring) | May 12 – Jul 12 |
| Onions | Start seeds indoors (spring) | Mar 31 – Apr 27 |
| Onions | Transplant outdoors (spring) | May 29 – Jun 27 |
| Broccoli | Start seeds indoors (spring) | Apr 24 – May 28 |
| Broccoli | Transplant outdoors (spring) | May 29 – Jun 27 |
| Broccoli | Start seeds indoors (fall) | May 13 – May 23 |
| Broccoli | Transplant outdoors (fall) | Jun 12 – Jun 23 |
| Cabbage | Start seeds indoors (spring) | Apr 14 – May 12 |
| Cabbage | Transplant outdoors (spring) | May 12 – Jun 12 |
| Cabbage | Start seeds indoors (fall) | May 3 – Jun 2 |
| Cabbage | Transplant outdoors (fall) | Jun 2 – Jul 3 |
| Leaf lettuce | Sow outdoors (spring) | May 12 – Jul 28 |
| Leaf lettuce | Sow outdoors (fall) | Jun 2 – Jul 19 |
| Spinach | Sow outdoors (spring) | May 5 – Jun 18 |
| Spinach | Sow outdoors (fall) | Jun 19 – Jul 24 |
| Radishes | Sow outdoors (spring) | May 12 – Jul 2 |
| Radishes | Sow outdoors (fall) | Jun 2 – Aug 3 |
| Kale | Sow outdoors (spring) | May 29 – Jun 18 |
| Kale | Sow outdoors (fall) | May 26 – Jul 3 |
| Carrots | Sow outdoors (spring) | Jun 12 – Jul 28 |
| Carrots | Sow outdoors (fall) | May 3 – Jun 18 |
| Garlic | Plant outdoors (fall) | Sep 2 – Oct 3 |
Where these dates come from
ZIP code 82931 is matched to the NOAA station Evanston 1 E, WY, 2.6 km away, at 6,825 ft elevation (58 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Evanston 1 E, WY (used) | 6,825 ft | Jun 12 | Sep 12 |
| Evanston Burns Fld, WY | 7,163 ft | Jun 3 | Sep 25 |
| Woodruff, UT | 6,315 ft | — | — |
| Coalville 13 E, UT | 6,510 ft | — | — |
Frost dates near Evanston
- Evanston, WY 82930 · last Jun 12, first Sep 12
- Woodruff, UT 84086 · last —, first —
- Robertson, WY 82944 · last Jun 11, first Sep 18
- Fort Bridger, WY 82933 · last Jun 14, first Sep 9
- Mountain View, WY 82939 · last Jun 14, first Sep 9
- Randolph, UT 84064 · last Jun 14, first Sep 1
- Lyman, WY 82937 · last Jun 14, first Sep 9
- Echo, UT 84024 · last May 30, first Sep 18
Frequently asked questions
- When is the last frost in Evanston, WY?
- For ZIP code 82931, the average last spring frost (32°F) is June 12, based on NOAA 1991-2020 climate normals for the Evanston 1 E, WY weather station. There is a 1-in-10 chance of a frost after July 2.
- When is the first frost in Evanston, WY?
- The average first fall frost (32°F) is September 12. There is a 1-in-10 chance of frost by August 26, so tender plants are at risk from that point on.
- How long is the growing season in 82931?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 90 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.