Frost dates for 83223Bloomington, ID
The average last spring frost in Bloomington is May 19 and the average first fall frost is September 21, giving a typical growing season of about 123 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 19
- Average first fall frost
- Sep 21
- Growing season
- 123 days
Safer after Jun 5 (1-in-10 risk)
Possible by Sep 5 (1-in-10 risk)
Last frost typically in 204 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 20 · Jun 6 · Jun 25 | Aug 25 · Sep 9 · Sep 22 | 92 days | 100% |
| Frost / freeze (32°F) | May 3 · May 19 · Jun 5 | Sep 5 · Sep 21 · Oct 5 | 123 days | 100% |
| Hard freeze (28°F) | Apr 20 · May 3 · May 20 | Sep 19 · Oct 3 · Oct 19 | 151 days | 100% |
Planting calendar for Bloomington
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 18 – Jun 24 |
| Tomatoes | Transplant outdoors | Jun 4 – Jun 1 |
| Peppers | Start seeds indoors | Apr 18 – May 19 |
| Peppers | Transplant outdoors | Jun 18 – Jul 19 |
| Eggplant | Start seeds indoors | May 5 – Jun 3 |
| Eggplant | Transplant outdoors | Jun 18 – Jul 19 |
| Cucumbers | Sow outdoors | Jun 18 – Jun 11 |
| Summer squash | Sow outdoors | Jun 4 – Jul 19 |
| Winter squash & pumpkins | Sow outdoors | Jun 18 – Jul 19 |
| Snap beans | Sow outdoors | Jun 4 – Jul 4 |
| Sweet corn | Sow outdoors | Jun 4 – Jun 1 |
| Watermelon & cantaloupe | Sow outdoors | Jun 18 – Jul 19 |
| Okra | Sow outdoors | Jun 11 – Jul 4 |
| Peas | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Potatoes | Plant outdoors (spring) | Apr 18 – Jun 18 |
| Onions | Start seeds indoors (spring) | Mar 7 – Apr 3 |
| Onions | Transplant outdoors (spring) | May 5 – Jun 3 |
| Broccoli | Start seeds indoors (spring) | Mar 31 – May 4 |
| Broccoli | Transplant outdoors (spring) | May 5 – Jun 3 |
| Broccoli | Start seeds indoors (fall) | May 22 – Jun 1 |
| Broccoli | Transplant outdoors (fall) | Jun 21 – Jul 2 |
| Cabbage | Start seeds indoors (spring) | Mar 21 – Apr 18 |
| Cabbage | Transplant outdoors (spring) | Apr 18 – May 19 |
| Cabbage | Start seeds indoors (fall) | May 12 – Jun 11 |
| Cabbage | Transplant outdoors (fall) | Jun 11 – Jul 12 |
| Leaf lettuce | Sow outdoors (spring) | Apr 18 – Jul 4 |
| Leaf lettuce | Sow outdoors (fall) | Jun 11 – Jul 28 |
| Spinach | Sow outdoors (spring) | Apr 11 – May 25 |
| Spinach | Sow outdoors (fall) | Jun 28 – Aug 2 |
| Radishes | Sow outdoors (spring) | Apr 18 – Jun 8 |
| Radishes | Sow outdoors (fall) | Jun 11 – Aug 12 |
| Kale | Sow outdoors (spring) | May 5 – May 25 |
| Kale | Sow outdoors (fall) | Jun 4 – Jul 12 |
| Carrots | Sow outdoors (spring) | May 19 – Jul 4 |
| Carrots | Sow outdoors (fall) | May 12 – Jun 27 |
| Garlic | Plant outdoors (fall) | Sep 11 – Oct 12 |
Where these dates come from
ZIP code 83223 is matched to the NOAA station Lifton Pumping Stn, ID, 10.4 km away, at 5,935 ft elevation (66 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Lifton Pumping Stn, ID (used) | 5,935 ft | May 19 | Sep 21 |
| Bern, ID | 5,964 ft | Jun 17 | Sep 3 |
| Bear Lake Sp, UT | 5,928 ft | May 15 | Oct 4 |
| Preston, ID | 4,719 ft | May 16 | Sep 28 |
Frost dates near Bloomington
- Paris, ID 83261 · last Jun 17, first Sep 3
- Saint Charles, ID 83272 · last May 19, first Sep 21
- Bern, ID 83220 · last Jun 17, first Sep 3
- Dingle, ID 83233 · last May 19, first Sep 21
- Fish Haven, ID 83287 · last May 15, first Oct 4
- Montpelier, ID 83254 · last Jun 17, first Sep 3
- Garden City, UT 84028 · last May 15, first Oct 4
- Geneva, ID 83238 · last Jun 17, first Sep 3
Frequently asked questions
- When is the last frost in Bloomington, ID?
- For ZIP code 83223, the average last spring frost (32°F) is May 19, based on NOAA 1991-2020 climate normals for the Lifton Pumping Stn, ID weather station. There is a 1-in-10 chance of a frost after June 5.
- When is the first frost in Bloomington, ID?
- The average first fall frost (32°F) is September 21. There is a 1-in-10 chance of frost by September 5, so tender plants are at risk from that point on.
- How long is the growing season in 83223?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 123 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.