USDA Hardiness Zone 5b
Frost Dates for 04210 — Auburn, Maine
NOAA 1991–2020 normals from Lewiston, ME (180 ft), 1 miles northeast.
Updated
In Auburn, the last spring frost (32°F) is around April 25 in half of years and has passed by May 6 in nine years out of ten. The first fall frost comes around October 19, as early as October 5 one year in ten, leaving a typical freeze-free season of 177 days (NOAA, Lewiston, ME).
- Last spring frost
- April 25
- First fall frost
- October 19
- Growing season
- 177 days
- Hardiness zone
- 5b
50% probability
50% probability
freeze-free, 50%
-15 to -10°F (-26.1 to -23.3°C) coldest night
- First snow
- November 13
- Last snow
- April 8
- Winters with snow
- 100%
- Snow per year
- 80.1"
median, 1991–2020
median, 1991–2020
23 of 23 observed
NOAA normal
Frost risk by date in Auburn
Half of springs at Lewiston, ME see their last 32°F night by April 25; only one in ten is past it by April 11, and one in ten still has one after May 6. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 2 20%, and after May 6 10%. The 11 days between the even-odds date and the one-in-ten date is narrower than at 87% of the 52 Maine stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 19 in half of years, as early as October 5 one year in ten, and holds off past November 3 one year in ten. A hard freeze of 28°F follows 13 days later, around November 1; in spring the one-in-ten date for 28°F is April 24, 12 days before the 32°F one. The freeze-free season lasts 177 days in a typical year, longer than at 94% of the 52 Maine stations; it reaches 198 days one year in ten and falls short of 159 one year in ten. On average 141 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 11 days longer, to about May 6, and return around October 6. Severe cold of 16°F or below comes every winter, usually between December 3 and March 20.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 25 | Apr 29 | May 1 | May 3 | May 6 | May 8 | May 11 | May 14 | May 18 |
| 32°F | Apr 11 | Apr 16 | Apr 20 | Apr 23 | Apr 25 | Apr 28 | Apr 30 | May 2 | May 6 |
| 28°F | Apr 2 | Apr 4 | Apr 6 | Apr 9 | Apr 11 | Apr 13 | Apr 17 | Apr 20 | Apr 24 |
| 24°F | Mar 20 | Mar 26 | Mar 30 | Apr 1 | Apr 3 | Apr 4 | Apr 5 | Apr 8 | Apr 13 |
| 20°F | Mar 14 | Mar 17 | Mar 20 | Mar 23 | Mar 26 | Mar 29 | Mar 31 | Apr 2 | Apr 5 |
| 16°F | Mar 8 | Mar 12 | Mar 14 | Mar 17 | Mar 20 | Mar 22 | Mar 25 | Mar 29 | Apr 1 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 27 | Oct 1 | Oct 2 | Oct 4 | Oct 6 | Oct 9 | Oct 11 | Oct 15 | Oct 21 |
| 32°F | Oct 5 | Oct 9 | Oct 13 | Oct 16 | Oct 19 | Oct 23 | Oct 26 | Oct 30 | Nov 3 |
| 28°F | Oct 17 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 10 | Nov 15 |
| 24°F | Nov 1 | Nov 5 | Nov 9 | Nov 11 | Nov 14 | Nov 16 | Nov 19 | Nov 23 | Nov 28 |
| 20°F | Nov 12 | Nov 16 | Nov 19 | Nov 22 | Nov 25 | Nov 28 | Nov 30 | Dec 3 | Dec 8 |
| 16°F | Nov 20 | Nov 25 | Nov 29 | Dec 1 | Dec 3 | Dec 5 | Dec 8 | Dec 12 | Dec 17 |
Freeze probabilities 1991–2020 at Lewiston, ME, 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 04210 →Compare Auburn with another place →
Weather by month in Auburn
July is the warmest month at Lewiston, ME, averaging 80°F by day and 62°F at night; January is the coldest at 28°F and 12°F. A freezing night is all but certain in every month from November to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 29% of years.
Warmth for growing adds up to 2,366 growing degree days a year (base 50°F), more than at 94% of the 52 Maine stations. 29% of them (675) have built up by the end of June, and July adds the most, 646. Precipitation totals 45.1 inches a year, most in October (4.9") and least in February (3.2"); May to September bring 40% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 28 | 12 | 3.3 | 100% | 30 | 0 |
| Feb | 32 | 14 | 3.2 | 100% | 26 | 0 |
| Mar | 40 | 23 | 3.5 | 100% | 25 | 1 |
| Apr | 53 | 35 | 4.0 | 100% | 10 | 27 |
| May | 65 | 46 | 3.2 | 29% | <1 | 198 |
| Jun | 74 | 56 | 4.3 | 0% | 0 | 449 |
| Jul | 80 | 62 | 3.5 | 0% | 0 | 646 |
| Aug | 79 | 60 | 3.4 | 0% | 0 | 614 |
| Sep | 70 | 52 | 3.7 | 2% | <1 | 341 |
| Oct | 58 | 41 | 4.9 | 81% | 5 | 83 |
| Nov | 45 | 31 | 3.9 | 100% | 17 | 7 |
| Dec | 34 | 20 | 4.2 | 100% | 27 | 0 |
Monthly normals 1991–2020 at Lewiston, ME (180 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, Poland, ME, 8 miles southwest of Auburn and 390 feet higher, has a last frost 8 days later (May 3), a first frost 12 days earlier (October 7), a season 20 days shorter.
When it snows in Auburn, Maine
The first measurable snow (0.1 inch or more) in Auburn usually arrives around November 13, and the last of the season around April 8. Those are the middle dates across the winters of 1991–2020 at Poland, ME, 8.2 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 17 days after the last snow.
Planting calendar for 04210
| When | What to do |
|---|---|
| February 14 – February 28 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 28 – March 14 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 28 – April 11 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 25 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 27 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 5 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 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 04210 is 1 mile from Lewiston, ME, which stands at 180 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station; its figures are presented in full for 04240 (Lewiston). The 2023 USDA Plant Hardiness Zone Map lists ZIP 04210 in zone 5b, the band where the coldest night of the year averaged -15 to -10°F (-26.1 to -23.3°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.