Frost dates for 84325Mendon, UT
The average last spring frost in Mendon is May 12 and the average first fall frost is September 28, giving a typical growing season of about 138 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 12
- Average first fall frost
- Sep 28
- Growing season
- 138 days
Safer after May 29 (1-in-10 risk)
Possible by Sep 14 (1-in-10 risk)
Last frost typically in 197 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 14 · May 31 · Jun 16 | Sep 4 · Sep 18 · Oct 2 | 109 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 12 · May 29 | Sep 14 · Sep 28 · Oct 12 | 138 days | 100% |
| Hard freeze (28°F) | Apr 9 · Apr 28 · May 12 | Sep 26 · Oct 9 · Oct 24 | 164 days | 100% |
Planting calendar for Mendon
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 11 – Jun 17 |
| Tomatoes | Transplant outdoors | May 28 – Jun 8 |
| Peppers | Start seeds indoors | Apr 11 – May 12 |
| Peppers | Transplant outdoors | Jun 11 – Jul 12 |
| Eggplant | Start seeds indoors | Apr 28 – May 27 |
| Eggplant | Transplant outdoors | Jun 11 – Jul 12 |
| Cucumbers | Sow outdoors | Jun 11 – Jun 18 |
| Summer squash | Sow outdoors | May 28 – Jul 12 |
| Winter squash & pumpkins | Sow outdoors | Jun 11 – Jul 12 |
| Snap beans | Sow outdoors | May 28 – Jul 11 |
| Sweet corn | Sow outdoors | May 28 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 11 – Jul 12 |
| Okra | Sow outdoors | Jun 4 – Jun 27 |
| Peas | Sow outdoors (spring) | Apr 11 – May 27 |
| Potatoes | Plant outdoors (spring) | Apr 11 – Jun 11 |
| Onions | Start seeds indoors (spring) | Feb 28 – Mar 27 |
| Onions | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (spring) | Mar 24 – Apr 27 |
| Broccoli | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 14 – Apr 11 |
| Cabbage | Transplant outdoors (spring) | Apr 11 – May 12 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 11 – Jun 27 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 4 – May 18 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 11 – Jun 1 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | Apr 28 – May 18 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 12 – Jun 27 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 84325 is matched to the NOAA station Logan 5 Sw Exp Farm, UT, 8.9 km away, at 4,488 ft elevation (66 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Logan 5 Sw Exp Farm, UT (used) | 4,488 ft | May 12 | Sep 28 |
| Logan Radio Kvnu, UT | 4,475 ft | May 8 | Oct 2 |
| Logan Cache Ap, UT | 4,454 ft | May 8 | Oct 2 |
| Cutler Dam, UT | 4,290 ft | May 3 | Oct 12 |
Frost dates near Mendon
- Wellsville, UT 84339 · last May 12, first Sep 28
- Deweyville, UT 84309 · last Apr 24, first Oct 17
- Logan, UT 84322 · last May 12, first Sep 28
- Collinston, UT 84306 · last Apr 30, first Oct 16
- Cache Junction, UT 84304 · last May 8, first Oct 2
- Honeyville, UT 84314 · last Apr 24, first Oct 17
- Millville, UT 84326 · last May 12, first Sep 28
- Hyrum, UT 84319 · last Apr 30, first Oct 16
Frequently asked questions
- When is the last frost in Mendon, UT?
- For ZIP code 84325, the average last spring frost (32°F) is May 12, based on NOAA 1991-2020 climate normals for the Logan 5 Sw Exp Farm, UT weather station. There is a 1-in-10 chance of a frost after May 29.
- When is the first frost in Mendon, UT?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 14, so tender plants are at risk from that point on.
- How long is the growing season in 84325?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 138 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.