Frost dates for 93546Mammoth Lakes, CA
The average last spring frost in Mammoth Lakes is June 10 and the average first fall frost is September 17, giving a typical growing season of about 98 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Jun 10
- Average first fall frost
- Sep 17
- Growing season
- 98 days
Safer after Jun 30 (1-in-10 risk)
Possible by Sep 2 (1-in-10 risk)
Last frost typically in 226 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) | — | — | 73 days | 100% |
| Frost / freeze (32°F) | May 29 · Jun 10 · Jun 30 | Sep 2 · Sep 17 · Oct 2 | 98 days | 100% |
| Hard freeze (28°F) | May 9 · May 31 · Jun 16 | Sep 15 · Oct 1 · Oct 16 | 124 days | 100% |
Planting calendar for Mammoth Lakes
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 | May 10 – Jul 16 |
| Tomatoes | Transplant outdoors | Jun 26 – May 28 |
| Peppers | Start seeds indoors | May 10 – Jun 10 |
| Peppers | Transplant outdoors | Jul 10 – Aug 10 |
| Eggplant | Start seeds indoors | May 27 – Jun 25 |
| Eggplant | Transplant outdoors | Jul 10 – Aug 10 |
| Cucumbers | Sow outdoors | Jul 10 – Jun 7 |
| Summer squash | Sow outdoors | Jun 26 – Aug 10 |
| Winter squash & pumpkins | Sow outdoors | Jul 10 – Aug 10 |
| Snap beans | Sow outdoors | Jun 26 – Jun 30 |
| Sweet corn | Sow outdoors | Jun 26 – May 28 |
| Watermelon & cantaloupe | Sow outdoors | Jul 10 – Aug 10 |
| Okra | Sow outdoors | Jul 3 – Jul 26 |
| Peas | Sow outdoors (spring) | May 10 – Jun 25 |
| Potatoes | Plant outdoors (spring) | May 10 – Jul 10 |
| Onions | Start seeds indoors (spring) | Mar 29 – Apr 25 |
| Onions | Transplant outdoors (spring) | May 27 – Jun 25 |
| Broccoli | Start seeds indoors (spring) | Apr 22 – May 26 |
| Broccoli | Transplant outdoors (spring) | May 27 – Jun 25 |
| Broccoli | Start seeds indoors (fall) | May 18 – May 28 |
| Broccoli | Transplant outdoors (fall) | Jun 17 – Jun 28 |
| Cabbage | Start seeds indoors (spring) | Apr 12 – May 10 |
| Cabbage | Transplant outdoors (spring) | May 10 – Jun 10 |
| Cabbage | Start seeds indoors (fall) | May 8 – Jun 7 |
| Cabbage | Transplant outdoors (fall) | Jun 7 – Jul 8 |
| Leaf lettuce | Sow outdoors (spring) | May 10 – Jul 26 |
| Leaf lettuce | Sow outdoors (fall) | Jun 7 – Jul 24 |
| Spinach | Sow outdoors (spring) | May 3 – Jun 16 |
| Spinach | Sow outdoors (fall) | Jun 24 – Jul 29 |
| Radishes | Sow outdoors (spring) | May 10 – Jun 30 |
| Radishes | Sow outdoors (fall) | Jun 7 – Aug 8 |
| Kale | Sow outdoors (spring) | May 27 – Jun 16 |
| Kale | Sow outdoors (fall) | May 31 – Jul 8 |
| Carrots | Sow outdoors (spring) | Jun 10 – Jul 26 |
| Carrots | Sow outdoors (fall) | May 8 – Jun 23 |
| Garlic | Plant outdoors (fall) | Sep 7 – Oct 8 |
Where these dates come from
ZIP code 93546 is matched to the NOAA station Mammoth Lakes Rs, CA, 9.5 km away, at 7,805 ft elevation (481 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Mammoth Lakes Rs, CA (used) | 7,805 ft | Jun 10 | Sep 17 |
| Lee Vining, CA | 6,797 ft | May 23 | Oct 9 |
| Tuolumne Meadows Rs, CA | 8,694 ft | — | — |
| Bishop Ap, CA | 4,102 ft | Apr 29 | Oct 15 |
Frost dates near Mammoth Lakes
- June Lake, CA 93529 · last Jun 10, first Sep 17
- Mono Hot Springs, CA 93642 · last Jun 1, first Oct 6
- Benton, CA 93512 · last May 23, first Oct 9
- Bishop, CA 93514 · last Apr 29, first Oct 15
- Lee Vining, CA 93541 · last May 23, first Oct 9
- Lakeshore, CA 93634 · last Jun 1, first Oct 6
- Big Creek, CA 93605 · last May 24, first Oct 10
- Shaver Lake, CA 93664 · last Jun 1, first Oct 6
Frequently asked questions
- When is the last frost in Mammoth Lakes, CA?
- For ZIP code 93546, the average last spring frost (32°F) is June 10, based on NOAA 1991-2020 climate normals for the Mammoth Lakes Rs, CA weather station. There is a 1-in-10 chance of a frost after June 30.
- When is the first frost in Mammoth Lakes, CA?
- The average first fall frost (32°F) is September 17. There is a 1-in-10 chance of frost by September 2, so tender plants are at risk from that point on.
- How long is the growing season in 93546?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 98 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.