Frost dates for 49276Riga, MI
The average last spring frost in Riga is April 29 and the average first fall frost is October 13, giving a typical growing season of about 168 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 29
- Average first fall frost
- Oct 13
- Growing season
- 168 days
Safer after May 15 (1-in-10 risk)
Possible by Sep 30 (1-in-10 risk)
Last frost typically in 178 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 25 · May 9 · May 24 | Sep 20 · Oct 2 · Oct 14 | 145 days | 100% |
| Frost / freeze (32°F) | Apr 15 · Apr 29 · May 15 | Sep 30 · Oct 13 · Oct 26 | 168 days | 100% |
| Hard freeze (28°F) | Apr 3 · Apr 16 · May 2 | Oct 11 · Oct 26 · Nov 7 | 192 days | 100% |
Planting calendar for Riga
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 29 – Jun 4 |
| Tomatoes | Transplant outdoors | May 15 – Jun 23 |
| Peppers | Start seeds indoors | Mar 29 – Apr 29 |
| Peppers | Transplant outdoors | May 29 – Jun 29 |
| Eggplant | Start seeds indoors | Apr 15 – May 14 |
| Eggplant | Transplant outdoors | May 29 – Jun 29 |
| Cucumbers | Sow outdoors | May 29 – Jul 3 |
| Summer squash | Sow outdoors | May 15 – Jun 29 |
| Winter squash & pumpkins | Sow outdoors | May 29 – Jun 29 |
| Snap beans | Sow outdoors | May 15 – Jul 26 |
| Sweet corn | Sow outdoors | May 15 – Jun 23 |
| Watermelon & cantaloupe | Sow outdoors | May 29 – Jun 29 |
| Okra | Sow outdoors | May 22 – Jun 14 |
| Peas | Sow outdoors (spring) | Mar 29 – May 14 |
| Potatoes | Plant outdoors (spring) | Mar 29 – May 29 |
| Onions | Start seeds indoors (spring) | Feb 15 – Mar 14 |
| Onions | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (spring) | Mar 11 – Apr 14 |
| Broccoli | Transplant outdoors (spring) | Apr 15 – May 14 |
| Broccoli | Start seeds indoors (fall) | Jun 13 – Jun 23 |
| Broccoli | Transplant outdoors (fall) | Jul 13 – Jul 24 |
| Cabbage | Start seeds indoors (spring) | Mar 1 – Mar 29 |
| Cabbage | Transplant outdoors (spring) | Mar 29 – Apr 29 |
| Cabbage | Start seeds indoors (fall) | Jun 3 – Jul 3 |
| Cabbage | Transplant outdoors (fall) | Jul 3 – Aug 3 |
| Leaf lettuce | Sow outdoors (spring) | Mar 29 – Jun 14 |
| Leaf lettuce | Sow outdoors (fall) | Jul 3 – Aug 19 |
| Spinach | Sow outdoors (spring) | Mar 22 – May 5 |
| Spinach | Sow outdoors (fall) | Jul 20 – Aug 24 |
| Radishes | Sow outdoors (spring) | Mar 29 – May 19 |
| Radishes | Sow outdoors (fall) | Jul 3 – Sep 3 |
| Kale | Sow outdoors (spring) | Apr 15 – May 5 |
| Kale | Sow outdoors (fall) | Jun 26 – Aug 3 |
| Carrots | Sow outdoors (spring) | Apr 29 – Jun 14 |
| Carrots | Sow outdoors (fall) | Jun 3 – Jul 19 |
| Garlic | Plant outdoors (fall) | Oct 3 – Nov 3 |
Where these dates come from
ZIP code 49276 is matched to the NOAA station Blissfield 1Nne, MI, 7 km away, at 690 ft elevation (9 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Blissfield 1Nne, MI (used) | 690 ft | Apr 29 | Oct 13 |
| Dundee, MI | 660 ft | Apr 27 | Oct 21 |
| Adrian 2 Nne, MI | 760 ft | May 1 | Oct 15 |
| Toledo Express Ap, OH | 669 ft | Apr 22 | Oct 24 |
Frost dates near Riga
- Blissfield, MI 49228 · last Apr 29, first Oct 13
- Ottawa Lake, MI 49267 · last Apr 27, first Oct 21
- Deerfield, MI 49238 · last Apr 27, first Oct 21
- Berkey, OH 43504 · last Apr 22, first Oct 24
- Sylvania, OH 43560 · last Apr 22, first Oct 24
- Petersburg, MI 49270 · last Apr 27, first Oct 21
- Palmyra, MI 49268 · last May 1, first Oct 15
- Metamora, OH 43540 · last Apr 22, first Oct 24
Frequently asked questions
- When is the last frost in Riga, MI?
- For ZIP code 49276, the average last spring frost (32°F) is April 29, based on NOAA 1991-2020 climate normals for the Blissfield 1Nne, MI weather station. There is a 1-in-10 chance of a frost after May 15.
- When is the first frost in Riga, MI?
- The average first fall frost (32°F) is October 13. There is a 1-in-10 chance of frost by September 30, so tender plants are at risk from that point on.
- How long is the growing season in 49276?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 168 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.