Frost dates for 73093Washington, OK
The average last spring frost in Washington is April 3 and the average first fall frost is November 3, giving a typical growing season of about 212 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 3
- Average first fall frost
- Nov 3
- Growing season
- 212 days
Safer after Apr 18 (1-in-10 risk)
Possible by Oct 21 (1-in-10 risk)
First frost typically in 1 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) | Mar 30 · Apr 14 · Apr 28 | Oct 11 · Oct 25 · Nov 6 | 193 days | 100% |
| Frost / freeze (32°F) | Mar 19 · Apr 3 · Apr 18 | Oct 21 · Nov 3 · Nov 17 | 212 days | 100% |
| Hard freeze (28°F) | Mar 5 · Mar 23 · Apr 7 | Oct 27 · Nov 12 · Nov 27 | 232 days | 100% |
Planting calendar for Washington
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 3 – May 9 |
| Tomatoes | Transplant outdoors | Apr 19 – Jul 14 |
| Peppers | Start seeds indoors | Mar 3 – Apr 3 |
| Peppers | Transplant outdoors | May 3 – Jun 3 |
| Eggplant | Start seeds indoors | Mar 20 – Apr 18 |
| Eggplant | Transplant outdoors | May 3 – Jun 3 |
| Cucumbers | Sow outdoors | May 3 – Jul 24 |
| Summer squash | Sow outdoors | Apr 19 – Jun 3 |
| Winter squash & pumpkins | Sow outdoors | May 3 – Jun 3 |
| Snap beans | Sow outdoors | Apr 19 – Aug 16 |
| Sweet corn | Sow outdoors | Apr 19 – Jul 14 |
| Watermelon & cantaloupe | Sow outdoors | May 3 – Jun 3 |
| Okra | Sow outdoors | Apr 26 – May 19 |
| Peas | Sow outdoors (spring) | Mar 3 – Apr 18 |
| Potatoes | Plant outdoors (spring) | Mar 3 – May 3 |
| Onions | Start seeds indoors (spring) | Jan 20 – Feb 16 |
| Onions | Transplant outdoors (spring) | Mar 20 – Apr 18 |
| Broccoli | Start seeds indoors (spring) | Feb 13 – Mar 19 |
| Broccoli | Transplant outdoors (spring) | Mar 20 – Apr 18 |
| Broccoli | Start seeds indoors (fall) | Jul 4 – Jul 14 |
| Broccoli | Transplant outdoors (fall) | Aug 3 – Aug 14 |
| Cabbage | Start seeds indoors (spring) | Feb 3 – Mar 3 |
| Cabbage | Transplant outdoors (spring) | Mar 3 – Apr 3 |
| Cabbage | Start seeds indoors (fall) | Jun 24 – Jul 24 |
| Cabbage | Transplant outdoors (fall) | Jul 24 – Aug 24 |
| Leaf lettuce | Sow outdoors (spring) | Mar 3 – May 19 |
| Leaf lettuce | Sow outdoors (fall) | Jul 24 – Sep 9 |
| Spinach | Sow outdoors (spring) | Feb 24 – Apr 9 |
| Spinach | Sow outdoors (fall) | Aug 10 – Sep 14 |
| Radishes | Sow outdoors (spring) | Mar 3 – Apr 23 |
| Radishes | Sow outdoors (fall) | Jul 24 – Sep 24 |
| Kale | Sow outdoors (spring) | Mar 20 – Apr 9 |
| Kale | Sow outdoors (fall) | Jul 17 – Aug 24 |
| Carrots | Sow outdoors (spring) | Apr 3 – May 19 |
| Carrots | Sow outdoors (fall) | Jun 24 – Aug 9 |
| Garlic | Plant outdoors (fall) | Oct 24 – Nov 24 |
Where these dates come from
ZIP code 73093 is matched to the NOAA station Norman 3Sse, OK, 7 km away, at 1,128 ft elevation (40 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Norman 3Sse, OK (used) | 1,128 ft | Apr 3 | Nov 3 |
| Norman 2Nw Mesonet, OK | 1,181 ft | Mar 31 | Nov 5 |
| Blanchard 2 Ssw, OK | 1,275 ft | Apr 3 | Nov 4 |
| Washington 6Ssw Mesonet, OK | 1,131 ft | Mar 31 | Nov 3 |
Frost dates near Washington
- Norman, OK 73072 · last Apr 3, first Nov 3
- Noble, OK 73068 · last Apr 3, first Nov 3
- Blanchard, OK 73010 · last Apr 3, first Nov 4
- Purcell, OK 73080 · last Apr 3, first Nov 3
- Newcastle, OK 73065 · last Apr 3, first Nov 4
- Dibble, OK 73031 · last Apr 3, first Nov 4
- Oklahoma City, OK 73160 · last Apr 4, first Nov 2
- Lexington, OK 73051 · last Apr 3, first Nov 3
Frequently asked questions
- When is the last frost in Washington, OK?
- For ZIP code 73093, the average last spring frost (32°F) is April 3, based on NOAA 1991-2020 climate normals for the Norman 3Sse, OK weather station. There is a 1-in-10 chance of a frost after April 18.
- When is the first frost in Washington, OK?
- The average first fall frost (32°F) is November 3. There is a 1-in-10 chance of frost by October 21, so tender plants are at risk from that point on.
- How long is the growing season in 73093?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 212 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.