Frost dates for 84302Brigham City, UT
The average last spring frost in Brigham City is May 5 and the average first fall frost is October 5, giving a typical growing season of about 150 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 5
- Average first fall frost
- Oct 5
- Growing season
- 150 days
Safer after May 29 (1-in-10 risk)
Possible by Sep 20 (1-in-10 risk)
Last frost typically in 190 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 5 · May 23 · Jun 11 | Sep 9 · Sep 24 · Oct 8 | 122 days | 100% |
| Frost / freeze (32°F) | Apr 20 · May 5 · May 29 | Sep 20 · Oct 5 · Oct 19 | 150 days | 100% |
| Hard freeze (28°F) | Mar 31 · Apr 18 · May 5 | Oct 1 · Oct 17 · Nov 1 | 181 days | 100% |
Planting calendar for Brigham City
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 4 – Jun 10 |
| Tomatoes | Transplant outdoors | May 21 – Jun 15 |
| Peppers | Start seeds indoors | Apr 4 – May 5 |
| Peppers | Transplant outdoors | Jun 4 – Jul 5 |
| Eggplant | Start seeds indoors | Apr 21 – May 20 |
| Eggplant | Transplant outdoors | Jun 4 – Jul 5 |
| Cucumbers | Sow outdoors | Jun 4 – Jun 25 |
| Summer squash | Sow outdoors | May 21 – Jul 5 |
| Winter squash & pumpkins | Sow outdoors | Jun 4 – Jul 5 |
| Snap beans | Sow outdoors | May 21 – Jul 18 |
| Sweet corn | Sow outdoors | May 21 – Jun 15 |
| Watermelon & cantaloupe | Sow outdoors | Jun 4 – Jul 5 |
| Okra | Sow outdoors | May 28 – Jun 20 |
| Peas | Sow outdoors (spring) | Apr 4 – May 20 |
| Potatoes | Plant outdoors (spring) | Apr 4 – Jun 4 |
| Onions | Start seeds indoors (spring) | Feb 21 – Mar 20 |
| Onions | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (spring) | Mar 17 – Apr 20 |
| Broccoli | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (fall) | Jun 5 – Jun 15 |
| Broccoli | Transplant outdoors (fall) | Jul 5 – Jul 16 |
| Cabbage | Start seeds indoors (spring) | Mar 7 – Apr 4 |
| Cabbage | Transplant outdoors (spring) | Apr 4 – May 5 |
| Cabbage | Start seeds indoors (fall) | May 26 – Jun 25 |
| Cabbage | Transplant outdoors (fall) | Jun 25 – Jul 26 |
| Leaf lettuce | Sow outdoors (spring) | Apr 4 – Jun 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 25 – Aug 11 |
| Spinach | Sow outdoors (spring) | Mar 28 – May 11 |
| Spinach | Sow outdoors (fall) | Jul 12 – Aug 16 |
| Radishes | Sow outdoors (spring) | Apr 4 – May 25 |
| Radishes | Sow outdoors (fall) | Jun 25 – Aug 26 |
| Kale | Sow outdoors (spring) | Apr 21 – May 11 |
| Kale | Sow outdoors (fall) | Jun 18 – Jul 26 |
| Carrots | Sow outdoors (spring) | May 5 – Jun 20 |
| Carrots | Sow outdoors (fall) | May 26 – Jul 11 |
| Garlic | Plant outdoors (fall) | Sep 25 – Oct 26 |
Where these dates come from
ZIP code 84302 is matched to the NOAA station Brigham City Waste Plt, UT, 3 km away, at 4,240 ft elevation (212 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Brigham City Waste Plt, UT (used) | 4,240 ft | May 5 | Oct 5 |
| Logan 5 Sw Exp Farm, UT | 4,488 ft | May 12 | Sep 28 |
| Eden-Liberty, UT | 5,195 ft | May 25 | Sep 26 |
| Tremonton, UT | 4,310 ft | Apr 24 | Oct 17 |
Frost dates near Brigham City
- Mantua, UT 84324 · last May 25, first Sep 26
- Corinne, UT 84307 · last May 5, first Oct 5
- Willard, UT 84340 · last Apr 21, first Oct 23
- Bear River City, UT 84301 · last May 5, first Oct 5
- Wellsville, UT 84339 · last May 12, first Sep 28
- Paradise, UT 84328 · last Apr 30, first Oct 16
- Honeyville, UT 84314 · last Apr 24, first Oct 17
- Logan, UT 84322 · last May 12, first Sep 28
Frequently asked questions
- When is the last frost in Brigham City, UT?
- For ZIP code 84302, the average last spring frost (32°F) is May 5, based on NOAA 1991-2020 climate normals for the Brigham City Waste Plt, UT weather station. There is a 1-in-10 chance of a frost after May 29.
- When is the first frost in Brigham City, UT?
- The average first fall frost (32°F) is October 5. There is a 1-in-10 chance of frost by September 20, so tender plants are at risk from that point on.
- How long is the growing season in 84302?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 150 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.