USDA Hardiness Zone 6a
Frost Dates for 46816 — Fort Wayne, Indiana
NOAA 1991–2020 normals from Fort Wayne International Airport, IN (791 ft), 8 miles west.
Updated
In Fort Wayne, the last spring frost (32°F) is around April 24 in half of years and has passed by May 10 in nine years out of ten. The first fall frost comes around October 21, as early as October 8 one year in ten, leaving a typical freeze-free season of 178 days (NOAA, Fort Wayne International Airport, IN).
- Last spring frost
- April 24
- First fall frost
- October 21
- Growing season
- 178 days
- Hardiness zone
- 6a
50% probability
50% probability
freeze-free, 50%
-10 to -5°F (-23.3 to -20.6°C) coldest night
- First snow
- November 16
- Last snow
- April 4
- Winters with snow
- 100%
- Snow per year
- 33.6"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Fort Wayne
Half of springs at Fort Wayne International Airport, IN see their last 32°F night by April 24; only one in ten is past it by April 10, and one in ten still has one after May 10. Planting tender crops after May 1 leaves a 30% risk of a frost on them, after May 5 20%, and after May 10 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 35% of the 125 Indiana stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 21 in half of years, as early as October 8 one year in ten, and holds off past November 1 one year in ten. A hard freeze of 28°F follows 11 days later, around November 1; in spring the one-in-ten date for 28°F is April 28, 12 days before the 32°F one. The freeze-free season lasts 178 days in a typical year, shorter than at 62% of the 125 Indiana stations; it reaches 199 days one year in ten and falls short of 157 one year in ten. On average 124 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 10 days longer, to about May 4, and return around October 9. Severe cold of 16°F or below comes every winter, usually between December 4 and March 10.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 20 | Apr 26 | Apr 29 | May 1 | May 4 | May 7 | May 10 | May 13 | May 18 |
| 32°F | Apr 10 | Apr 15 | Apr 18 | Apr 21 | Apr 24 | Apr 28 | May 1 | May 5 | May 10 |
| 28°F | Mar 28 | Apr 2 | Apr 5 | Apr 8 | Apr 12 | Apr 15 | Apr 18 | Apr 22 | Apr 28 |
| 24°F | Mar 16 | Mar 21 | Mar 26 | Mar 29 | Mar 31 | Apr 3 | Apr 6 | Apr 9 | Apr 15 |
| 20°F | Mar 4 | Mar 10 | Mar 14 | Mar 17 | Mar 20 | Mar 24 | Mar 27 | Mar 31 | Apr 3 |
| 16°F | Feb 22 | Mar 1 | Mar 4 | Mar 8 | Mar 10 | Mar 14 | Mar 17 | Mar 21 | Mar 27 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 25 | Sep 30 | Oct 3 | Oct 6 | Oct 9 | Oct 12 | Oct 14 | Oct 17 | Oct 22 |
| 32°F | Oct 8 | Oct 12 | Oct 16 | Oct 18 | Oct 21 | Oct 23 | Oct 25 | Oct 29 | Nov 1 |
| 28°F | Oct 19 | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 11 | Nov 16 |
| 24°F | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 23 | Nov 29 |
| 20°F | Nov 8 | Nov 12 | Nov 17 | Nov 21 | Nov 24 | Nov 28 | Dec 1 | Dec 6 | Dec 14 |
| 16°F | Nov 16 | Nov 23 | Nov 27 | Dec 1 | Dec 4 | Dec 8 | Dec 13 | Dec 19 | Dec 25 |
Freeze probabilities 1991–2020 at Fort Wayne International Airport, IN, 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 46816 →Compare Fort Wayne with another place →
Weather by month in Fort Wayne
July is the warmest month at Fort Wayne International Airport, IN, averaging 84°F by day and 64°F at night; January is the coldest at 33°F and 18°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 32% of years.
Warmth for growing adds up to 3,178 growing degree days a year (base 50°F), fewer than at 66% of the 125 Indiana stations. 35% of them (1,125) have built up by the end of June, and July adds the most, 738. Precipitation totals 39.6 inches a year, most in May (4.6") and least in February (2.1"); May to September bring 51% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 33 | 18 | 2.5 | 100% | 28 | 2 |
| Feb | 37 | 21 | 2.1 | 100% | 24 | 3 |
| Mar | 48 | 29 | 2.8 | 100% | 21 | 27 |
| Apr | 61 | 39 | 3.7 | 98% | 7 | 115 |
| May | 72 | 50 | 4.6 | 32% | <1 | 359 |
| Jun | 81 | 60 | 4.5 | 0% | 0 | 619 |
| Jul | 84 | 64 | 4.1 | 0% | 0 | 738 |
| Aug | 82 | 61 | 3.8 | 0% | 0 | 670 |
| Sep | 76 | 53 | 3.0 | 2% | <1 | 445 |
| Oct | 64 | 43 | 3.0 | 86% | 4 | 167 |
| Nov | 49 | 33 | 3.0 | 100% | 15 | 30 |
| Dec | 38 | 24 | 2.5 | 100% | 25 | 4 |
Monthly normals 1991–2020 at Fort Wayne International Airport, IN (791 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, Decatur 1 N, IN, 13 miles southeast of Fort Wayne, has a last frost 1 day earlier (April 23), a first frost 2 days earlier (October 19).
When it snows in Fort Wayne, Indiana
The first measurable snow (0.1 inch or more) in Fort Wayne usually arrives around November 16, and the last of the season around April 4. Those are the middle dates across the winters of 1991–2020 at Fort Wayne International Airport, IN, 7.6 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 20 days after the last snow.
Planting calendar for 46816
| When | What to do |
|---|---|
| February 13 – February 27 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 27 – March 13 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 27 – April 10 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 24 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 29 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 7 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 21 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 46816 is 8 miles from Fort Wayne International Airport, IN, which stands at 791 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 13 other ZIP codes share the station; its figures are presented in full for 46804 (Fort Wayne). The 2023 USDA Plant Hardiness Zone Map lists ZIP 46816 in zone 6a, the band where the coldest night of the year averaged -10 to -5°F (-23.3 to -20.6°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.