Anaconda, MT frost dates
How Anaconda compares
- In 8 years out of 10, the last spring frost in Anaconda falls between May 14 and June 25, a 42-day window. The first fall frost falls between August 31 and October 1.
- The median last frost is 13 days later than the Montana median of May 19.
- Its 105-day growing season is longer than 17% of the 325 Montana places with a regular frost season (state median 125 days).
- The last frost is 29 days later than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 201 nights a year at or below 32°F.
- Compared with Missoula, MT, 116 km away, the last frost here is 22 days later than there and the growing season is 39 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 14 |
| 50% (median) | June 1 |
| 10% (safe for tender plants) | June 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | August 31 |
| 50% (median) | September 14 |
| 90% (late) | October 1 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Anaconda, MT
Anaconda, MT frost dates — last frost Jun 1, first frost Sep 14, zone 5a. whenisthelastfrost.com
When to plant vegetables in Anaconda, MT
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Mar 9 – Mar 23 | May 4 – May 18 | — | — |
| Peppers | Mar 23 – Apr 6 | Jun 15 – Jun 29 | — | — |
| Eggplant | Mar 23 – Apr 6 | Jun 15 – Jun 29 | — | — |
| Tomatoes | Apr 6 – Apr 20 | Jun 8 – Jun 22 | — | — |
| Lettuce | Apr 6 – Apr 20 | May 11 – May 25 | May 4 – Jun 8 | Jul 20 – Aug 17 |
| Kale | Apr 6 – Apr 20 | May 4 – May 18 | May 4 – May 18 | Jul 6 – Jul 27 |
| Broccoli | Apr 6 – Apr 20 | May 18 – Jun 1 | — | — |
| Cabbage | Apr 6 – Apr 20 | May 11 – May 25 | — | — |
| Cauliflower | Apr 6 – Apr 20 | May 18 – Jun 1 | — | — |
| Okra | Apr 20 – May 4 | Jun 22 – Jul 6 | Jun 22 – Jul 6 | — |
| Basil | Apr 20 – May 4 | Jun 8 – Jun 22 | — | — |
| Peas | — | — | Apr 20 – May 11 | Jun 22 – Jul 13 |
| Spinach | — | — | Apr 20 – May 11 | Jul 20 – Aug 10 |
| Radishes | — | — | Apr 27 – Jun 8 | Aug 3 – Aug 24 |
| Cucumbers | May 4 – May 11 | Jun 15 – Jun 22 | Jun 8 – Jun 22 | — |
| Zucchini & Summer Squash | May 4 – May 11 | — | Jun 8 – Jun 22 | — |
| Winter Squash & Pumpkins Warning: Your frost-free season is about 105 days, which is tight for winter squash & pumpkins (100+ days). Choose early varieties and use transplants or row covers. | May 4 – May 11 | — | Jun 8 – Jun 22 | — |
| Melons & Watermelon | May 4 – May 11 | Jun 15 – Jun 29 | — | — |
| Carrots | — | — | May 11 – Jun 8 | — |
| Beets | — | — | May 11 – Jun 8 | Jul 6 – Jul 20 |
| Potatoes | — | — | May 11 – Jun 1 | — |
| Swiss Chard | — | — | May 18 – Jun 15 | Jul 6 – Jul 20 |
| Cilantro | — | — | May 18 – Jun 8 | Jul 20 – Aug 10 |
| Green Beans | — | — | Jun 8 – Jun 29 | — |
| Sweet Corn | — | — | Jun 8 – Jun 22 | — |
| Sweet Potatoes Warning: Your frost-free season is about 105 days, which is tight for sweet potatoes (100+ days). Choose early varieties and use transplants or row covers. | — | Jun 15 – Jul 6 | — | — |
| Garlic | — | — | — | Aug 31 – Oct 5 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Anaconda, MT weather station, 3 km away (elevation 5,230 ft (1,594 m)).
Frost dates near Anaconda
- Warm Springs Jun 1 · Sep 14
- Ramsay Jun 13 · Sep 5
- Butte Jun 13 · Sep 5
- Philipsburg frost any month
- Deer Lodge frost any month
- Divide Jun 10 · Sep 7
- Wise River frost any month
- Gold Creek frost any month
- Hall frost any month
- Garrison frost any month
Frequently asked questions
When is the last frost in Anaconda, MT?
The median last spring frost in Anaconda, MT is June 1. There is still about a 10% chance of frost after June 25, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Anaconda, MT?
The median first fall frost is September 14, with about a 10% chance of frost before August 31.
How long is the growing season in Anaconda, MT?
About 105 days between the median last spring frost and first fall frost.
What planting zone is Anaconda, MT?
Anaconda, MT is in USDA hardiness zone 5a.