USDA Hardiness Zone 5a
Frost Dates for 59068 — Red Lodge, Montana
NOAA 1991–2020 normals from Red Lodge, MT (5,646 ft), 6 miles southeast.
Updated
In Red Lodge, the last spring frost (32°F) is around June 3 in half of years and has passed by June 18 in nine years out of ten. The first fall frost comes around September 19, as early as August 31 one year in ten, leaving a typical freeze-free season of 106 days (NOAA, Red Lodge, MT).
- Last spring frost
- June 3
- First fall frost
- September 19
- Growing season
- 106 days
- Hardiness zone
- 5a
50% probability
50% probability
freeze-free, 50%
-20 to -15°F (-28.9 to -26.1°C) coldest night
- First snow
- October 2
- Last snow
- May 12
- Winters with snow
- 100%
- Snow per year
- 141.9"
median, 1991–2020
median, 1991–2020
28 of 28 observed
NOAA normal
Frost risk by date in Red Lodge
Half of springs at Red Lodge, MT see their last 32°F night by June 3; only one in ten is past it by May 19, and one in ten still has one after June 18. Planting tender crops after June 9 leaves a 30% risk of a frost on them, after June 13 20%, and after June 18 10%. The 15 days between the even-odds date and the one-in-ten date is narrower than at 53% of the 68 Montana stations behind this site's ZIP pages.
In fall the first 32°F night comes by September 19 in half of years, as early as August 31 one year in ten, and holds off past October 3 one year in ten. A hard freeze of 28°F follows 12 days later, around October 1; in spring the one-in-ten date for 28°F is June 4, 14 days before the 32°F one. The freeze-free season lasts 106 days in a typical year, shorter than at 85% of the 68 Montana stations; it reaches 127 days one year in ten and falls short of 81 one year in ten. On average 192 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 16 days longer, to about June 19, and return around September 5. Severe cold of 16°F or below comes every winter, usually between October 28 and April 8.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Jun 3 | Jun 9 | Jun 12 | Jun 16 | Jun 19 | Jun 21 | Jun 24 | Jun 30 | Jul 7 |
| 32°F | May 19 | May 24 | May 28 | May 31 | Jun 3 | Jun 5 | Jun 9 | Jun 13 | Jun 18 |
| 28°F | May 1 | May 5 | May 10 | May 14 | May 17 | May 22 | May 25 | May 30 | Jun 4 |
| 24°F | Apr 18 | Apr 23 | Apr 27 | Apr 30 | May 3 | May 6 | May 9 | May 14 | May 22 |
| 20°F | Apr 4 | Apr 9 | Apr 13 | Apr 17 | Apr 20 | Apr 23 | Apr 27 | Apr 30 | May 5 |
| 16°F | Mar 21 | Mar 28 | Apr 1 | Apr 4 | Apr 8 | Apr 12 | Apr 15 | Apr 19 | Apr 24 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 14 | Aug 23 | Aug 28 | Sep 2 | Sep 5 | Sep 8 | Sep 12 | Sep 16 | Sep 22 |
| 32°F | Aug 31 | Sep 6 | Sep 12 | Sep 15 | Sep 19 | Sep 23 | Sep 26 | Sep 30 | Oct 3 |
| 28°F | Sep 15 | Sep 21 | Sep 25 | Sep 28 | Oct 1 | Oct 3 | Oct 5 | Oct 9 | Oct 14 |
| 24°F | Sep 27 | Oct 1 | Oct 4 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 20 | Oct 26 |
| 20°F | Oct 4 | Oct 8 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 | Oct 31 | Nov 5 |
| 16°F | Oct 10 | Oct 16 | Oct 20 | Oct 24 | Oct 28 | Nov 1 | Nov 4 | Nov 9 | Nov 14 |
Freeze probabilities 1991–2020 at Red Lodge, MT, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 59068 →Compare Red Lodge with another place →
Weather by month in Red Lodge
July is the warmest month at Red Lodge, MT, averaging 81°F by day and 50°F at night; December is the coldest at 36°F and 14°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). July is the only month with under a 10% chance of a 32°F night. In spring, June still brings one in 58% of years.
Warmth for growing adds up to 1,598 growing degree days a year (base 50°F), fewer than at 81% of the 68 Montana stations. 23% of them (368) have built up by the end of June, and July adds the most, 483. Precipitation totals 22.6 inches a year, most in May (4.7") and least in January (0.8"); May to September bring 50% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 38 | 14 | 0.8 | 100% | 30 | 0 |
| Feb | 37 | 14 | 1.1 | 100% | 27 | 1 |
| Mar | 46 | 22 | 1.8 | 100% | 27 | 3 |
| Apr | 53 | 29 | 2.8 | 100% | 21 | 22 |
| May | 62 | 37 | 4.7 | 99% | 9 | 95 |
| Jun | 72 | 44 | 2.6 | 58% | 2 | 247 |
| Jul | 81 | 50 | 1.5 | 0% | 0 | 483 |
| Aug | 81 | 49 | 1.0 | 11% | <1 | 458 |
| Sep | 71 | 42 | 1.6 | 80% | 4 | 232 |
| Oct | 56 | 31 | 2.3 | 100% | 17 | 53 |
| Nov | 43 | 21 | 1.4 | 100% | 26 | 5 |
| Dec | 36 | 14 | 1.0 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Red Lodge, MT (5,646 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Joliet, MT, 22 miles northeast of Red Lodge and 1,808 feet lower, has a last frost 5 days earlier (May 29), a first frost 4 days earlier (September 15), a season 1 day longer.
When it snows in Red Lodge, Montana
The first measurable snow (0.1 inch or more) in Red Lodge usually arrives around October 2, and the last of the season around May 12. Those are the middle dates across the winters of 1991–2020 at Red Lodge, MT, 5.5 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 22 days after the last snow.
Planting calendar for 59068
| When | What to do |
|---|---|
| March 25 – April 8 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| April 8 – April 22 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| May 6 – May 20 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| June 3 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by June 27 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 5 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 19 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 59068 is 6 miles from Red Lodge, MT, which stands at 5,646 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 59068 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°C) over 1991–2020; a zone describes winter lows, not frost dates.
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.