Frost dates for 98231Blaine, WA
The average last spring frost in Blaine is March 31 and the average first fall frost is November 4, giving a typical growing season of about 219 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Mar 31
- Average first fall frost
- Nov 4
- Growing season
- 219 days
Safer after Apr 22 (1-in-10 risk)
Possible by Oct 18 (1-in-10 risk)
First frost typically in 3 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 1 · Apr 23 · May 12 | Oct 4 · Oct 20 · Nov 6 | 182 days | 100% |
| Frost / freeze (32°F) | Mar 8 · Mar 31 · Apr 22 | Oct 18 · Nov 4 · Nov 24 | 219 days | 100% |
| Hard freeze (28°F) | Feb 2 · Mar 5 · Mar 31 | Oct 30 · Nov 19 · Dec 16 | 257 days | 100% |
Planting calendar for Blaine
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 | Feb 28 – May 6 |
| Tomatoes | Transplant outdoors | Apr 16 – Jul 15 |
| Peppers | Start seeds indoors | Feb 28 – Mar 31 |
| Peppers | Transplant outdoors | Apr 30 – May 31 |
| Eggplant | Start seeds indoors | Mar 17 – Apr 15 |
| Eggplant | Transplant outdoors | Apr 30 – May 31 |
| Cucumbers | Sow outdoors | Apr 30 – Jul 25 |
| Summer squash | Sow outdoors | Apr 16 – May 31 |
| Winter squash & pumpkins | Sow outdoors | Apr 30 – May 31 |
| Snap beans | Sow outdoors | Apr 16 – Aug 17 |
| Sweet corn | Sow outdoors | Apr 16 – Jul 15 |
| Watermelon & cantaloupe | Sow outdoors | Apr 30 – May 31 |
| Okra | Sow outdoors | Apr 23 – May 16 |
| Peas | Sow outdoors (spring) | Feb 28 – Apr 15 |
| Potatoes | Plant outdoors (spring) | Feb 28 – Apr 30 |
| Onions | Start seeds indoors (spring) | Jan 17 – Feb 13 |
| Onions | Transplant outdoors (spring) | Mar 17 – Apr 15 |
| Broccoli | Start seeds indoors (spring) | Feb 10 – Mar 16 |
| Broccoli | Transplant outdoors (spring) | Mar 17 – Apr 15 |
| Broccoli | Start seeds indoors (fall) | Jul 5 – Jul 15 |
| Broccoli | Transplant outdoors (fall) | Aug 4 – Aug 15 |
| Cabbage | Start seeds indoors (spring) | Jan 31 – Feb 28 |
| Cabbage | Transplant outdoors (spring) | Feb 28 – Mar 31 |
| Cabbage | Start seeds indoors (fall) | Jun 25 – Jul 25 |
| Cabbage | Transplant outdoors (fall) | Jul 25 – Aug 25 |
| Leaf lettuce | Sow outdoors (spring) | Feb 28 – May 16 |
| Leaf lettuce | Sow outdoors (fall) | Jul 25 – Sep 10 |
| Spinach | Sow outdoors (spring) | Feb 21 – Apr 6 |
| Spinach | Sow outdoors (fall) | Aug 11 – Sep 15 |
| Radishes | Sow outdoors (spring) | Feb 28 – Apr 20 |
| Radishes | Sow outdoors (fall) | Jul 25 – Sep 25 |
| Kale | Sow outdoors (spring) | Mar 17 – Apr 6 |
| Kale | Sow outdoors (fall) | Jul 18 – Aug 25 |
| Carrots | Sow outdoors (spring) | Mar 31 – May 16 |
| Carrots | Sow outdoors (fall) | Jun 25 – Aug 10 |
| Garlic | Plant outdoors (fall) | Oct 25 – Nov 25 |
Where these dates come from
ZIP code 98231 is matched to the NOAA station Blaine, WA, 3.8 km away, at 60 ft elevation (14 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Blaine, WA (used) | 60 ft | Mar 31 | Nov 4 |
| Bellingham Intl Ap, WA | 149 ft | Mar 31 | Oct 30 |
| Clearbrook, WA | 64 ft | Apr 18 | Oct 18 |
| Bellingham 3 Ssw, WA | 15 ft | Apr 1 | Nov 2 |
Frost dates near Blaine
- Blaine, WA 98230 · last Mar 31, first Nov 4
- Custer, WA 98240 · last Mar 31, first Nov 4
- Ferndale, WA 98248 · last Mar 31, first Oct 30
- Lynden, WA 98264 · last Apr 18, first Oct 18
- Point Roberts, WA 98281 · last Mar 31, first Nov 4
- Bellingham, WA 98226 · last Mar 31, first Oct 30
- Lummi Island, WA 98262 · last Feb 26, first Nov 29
- Everson, WA 98247 · last Apr 18, first Oct 18
Frequently asked questions
- When is the last frost in Blaine, WA?
- For ZIP code 98231, the average last spring frost (32°F) is March 31, based on NOAA 1991-2020 climate normals for the Blaine, WA weather station. There is a 1-in-10 chance of a frost after April 22.
- When is the first frost in Blaine, WA?
- The average first fall frost (32°F) is November 4. There is a 1-in-10 chance of frost by October 18, so tender plants are at risk from that point on.
- How long is the growing season in 98231?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 219 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.