Frost dates for 55902Rochester, MN
The average last spring frost in Rochester is May 12 and the average first fall frost is September 28, giving a typical growing season of about 139 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 12
- Average first fall frost
- Sep 28
- Growing season
- 139 days
Safer after May 25 (1-in-10 risk)
Possible by Sep 14 (1-in-10 risk)
Last frost typically in 197 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 8 · May 22 · Jun 4 | Sep 5 · Sep 19 · Oct 2 | 120 days | 100% |
| Frost / freeze (32°F) | Apr 29 · May 12 · May 25 | Sep 14 · Sep 28 · Oct 10 | 139 days | 100% |
| Hard freeze (28°F) | Apr 18 · May 2 · May 15 | Sep 22 · Oct 5 · Oct 18 | 156 days | 100% |
Planting calendar for Rochester
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 11 – Jun 17 |
| Tomatoes | Transplant outdoors | May 28 – Jun 8 |
| Peppers | Start seeds indoors | Apr 11 – May 12 |
| Peppers | Transplant outdoors | Jun 11 – Jul 12 |
| Eggplant | Start seeds indoors | Apr 28 – May 27 |
| Eggplant | Transplant outdoors | Jun 11 – Jul 12 |
| Cucumbers | Sow outdoors | Jun 11 – Jun 18 |
| Summer squash | Sow outdoors | May 28 – Jul 12 |
| Winter squash & pumpkins | Sow outdoors | Jun 11 – Jul 12 |
| Snap beans | Sow outdoors | May 28 – Jul 11 |
| Sweet corn | Sow outdoors | May 28 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 11 – Jul 12 |
| Okra | Sow outdoors | Jun 4 – Jun 27 |
| Peas | Sow outdoors (spring) | Apr 11 – May 27 |
| Potatoes | Plant outdoors (spring) | Apr 11 – Jun 11 |
| Onions | Start seeds indoors (spring) | Feb 28 – Mar 27 |
| Onions | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (spring) | Mar 24 – Apr 27 |
| Broccoli | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 14 – Apr 11 |
| Cabbage | Transplant outdoors (spring) | Apr 11 – May 12 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 11 – Jun 27 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 4 – May 18 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 11 – Jun 1 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | Apr 28 – May 18 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 12 – Jun 27 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 55902 is matched to the NOAA station Byron 4North, MN, 15.9 km away, at 1,041 ft elevation (34 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Byron 4North, MN (used) | 1,041 ft | May 12 | Sep 28 |
| Rochester Intl Ap, MN | 1,304 ft | Apr 30 | Oct 6 |
| Grand Meadow, MN | 1,350 ft | May 6 | Oct 1 |
| Zumbrota, MN | 970 ft | May 9 | Sep 30 |
Frost dates near Rochester
- Rochester, MN 55905 · last May 12, first Sep 28
- Byron, MN 55920 · last May 12, first Sep 28
- Oronoco, MN 55960 · last May 12, first Sep 28
- Stewartville, MN 55976 · last Apr 30, first Oct 6
- Eyota, MN 55934 · last Apr 30, first Oct 6
- Kasson, MN 55944 · last May 12, first Sep 28
- Mantorville, MN 55955 · last May 12, first Sep 28
- Elgin, MN 55932 · last May 7, first Oct 2
Frequently asked questions
- When is the last frost in Rochester, MN?
- For ZIP code 55902, the average last spring frost (32°F) is May 12, based on NOAA 1991-2020 climate normals for the Byron 4North, MN weather station. There is a 1-in-10 chance of a frost after May 25.
- When is the first frost in Rochester, MN?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 14, so tender plants are at risk from that point on.
- How long is the growing season in 55902?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 139 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.