Frost dates for 66942Formoso, KS
The average last spring frost in Formoso is April 17 and the average first fall frost is October 21, giving a typical growing season of about 187 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 17
- Average first fall frost
- Oct 21
- Growing season
- 187 days
Safer after Apr 29 (1-in-10 risk)
Possible by Oct 5 (1-in-10 risk)
Last frost typically in 167 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) | Apr 13 · Apr 26 · May 7 | Sep 27 · Oct 12 · Oct 25 | 169 days | 100% |
| Frost / freeze (32°F) | Apr 2 · Apr 17 · Apr 29 | Oct 5 · Oct 21 · Nov 4 | 187 days | 100% |
| Hard freeze (28°F) | Mar 21 · Apr 8 · Apr 22 | Oct 16 · Nov 1 · Nov 16 | 206 days | 100% |
Planting calendar for Formoso
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 | Mar 17 – May 23 |
| Tomatoes | Transplant outdoors | May 3 – Jul 1 |
| Peppers | Start seeds indoors | Mar 17 – Apr 17 |
| Peppers | Transplant outdoors | May 17 – Jun 17 |
| Eggplant | Start seeds indoors | Apr 3 – May 2 |
| Eggplant | Transplant outdoors | May 17 – Jun 17 |
| Cucumbers | Sow outdoors | May 17 – Jul 11 |
| Summer squash | Sow outdoors | May 3 – Jun 17 |
| Winter squash & pumpkins | Sow outdoors | May 17 – Jun 17 |
| Snap beans | Sow outdoors | May 3 – Aug 3 |
| Sweet corn | Sow outdoors | May 3 – Jul 1 |
| Watermelon & cantaloupe | Sow outdoors | May 17 – Jun 17 |
| Okra | Sow outdoors | May 10 – Jun 2 |
| Peas | Sow outdoors (spring) | Mar 17 – May 2 |
| Potatoes | Plant outdoors (spring) | Mar 17 – May 17 |
| Onions | Start seeds indoors (spring) | Feb 3 – Mar 2 |
| Onions | Transplant outdoors (spring) | Apr 3 – May 2 |
| Broccoli | Start seeds indoors (spring) | Feb 27 – Apr 2 |
| Broccoli | Transplant outdoors (spring) | Apr 3 – May 2 |
| Broccoli | Start seeds indoors (fall) | Jun 21 – Jul 1 |
| Broccoli | Transplant outdoors (fall) | Jul 21 – Aug 1 |
| Cabbage | Start seeds indoors (spring) | Feb 17 – Mar 17 |
| Cabbage | Transplant outdoors (spring) | Mar 17 – Apr 17 |
| Cabbage | Start seeds indoors (fall) | Jun 11 – Jul 11 |
| Cabbage | Transplant outdoors (fall) | Jul 11 – Aug 11 |
| Leaf lettuce | Sow outdoors (spring) | Mar 17 – Jun 2 |
| Leaf lettuce | Sow outdoors (fall) | Jul 11 – Aug 27 |
| Spinach | Sow outdoors (spring) | Mar 10 – Apr 23 |
| Spinach | Sow outdoors (fall) | Jul 28 – Sep 1 |
| Radishes | Sow outdoors (spring) | Mar 17 – May 7 |
| Radishes | Sow outdoors (fall) | Jul 11 – Sep 11 |
| Kale | Sow outdoors (spring) | Apr 3 – Apr 23 |
| Kale | Sow outdoors (fall) | Jul 4 – Aug 11 |
| Carrots | Sow outdoors (spring) | Apr 17 – Jun 2 |
| Carrots | Sow outdoors (fall) | Jun 11 – Jul 27 |
| Garlic | Plant outdoors (fall) | Oct 11 – Nov 11 |
Where these dates come from
ZIP code 66942 is matched to the NOAA station Courtland, KS, 8 km away, at 1,500 ft elevation (6 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Courtland, KS (used) | 1,500 ft | Apr 17 | Oct 21 |
| Lovewell Dam, KS | 1,602 ft | Apr 20 | Oct 19 |
| Mankato, KS | 1,750 ft | Apr 30 | Oct 14 |
| Superior, NE | 1,512 ft | Apr 29 | Oct 10 |
Frost dates near Formoso
- Courtland, KS 66939 · last Apr 17, first Oct 21
- Webber, KS 66970 · last Apr 20, first Oct 19
- Randall, KS 66963 · last Apr 17, first Oct 21
- Scandia, KS 66966 · last Apr 17, first Oct 21
- Jewell, KS 66949 · last Apr 17, first Oct 21
- Mankato, KS 66956 · last Apr 30, first Oct 8
- Republic, KS 66964 · last Apr 17, first Oct 21
- Jamestown, KS 66948 · last Apr 21, first Oct 19
Frequently asked questions
- When is the last frost in Formoso, KS?
- For ZIP code 66942, the average last spring frost (32°F) is April 17, based on NOAA 1991-2020 climate normals for the Courtland, KS weather station. There is a 1-in-10 chance of a frost after April 29.
- When is the first frost in Formoso, KS?
- The average first fall frost (32°F) is October 21. There is a 1-in-10 chance of frost by October 5, so tender plants are at risk from that point on.
- How long is the growing season in 66942?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 187 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.