USDA Hardiness Zone 6a
Frost Dates for 46582 — Warsaw, Indiana
NOAA 1991–2020 normals from Warsaw, IN (815 ft), 3 miles southwest.
Updated
In Warsaw, the last spring frost (32°F) is around April 28 in half of years and has passed by May 14 in nine years out of ten. The first fall frost comes around October 18, as early as October 1 one year in ten, leaving a typical freeze-free season of 170 days (NOAA, Warsaw, IN).
- Last spring frost
- April 28
- First fall frost
- October 18
- Growing season
- 170 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
- December 7
- Last snow
- March 12
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
26 of 26 observed
NOAA normal
Frost risk by date in Warsaw
Half of springs at Warsaw, IN see their last 32°F night by April 28; only one in ten is past it by April 13, and one in ten still has one after May 14. Planting tender crops after May 4 leaves a 30% risk of a frost on them, after May 8 20%, and after May 14 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 18 in half of years, as early as October 1 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 12 days later, around October 30; in spring the one-in-ten date for 28°F is May 4, 10 days before the 32°F one. The freeze-free season lasts 170 days in a typical year, shorter than at 89% of the 125 Indiana stations; it reaches 191 days one year in ten and falls short of 149 one year in ten. On average 132 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 9, and return around October 5. Severe cold of 16°F or below comes every winter, usually between December 2 and March 15.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 23 | Apr 29 | May 2 | May 6 | May 9 | May 12 | May 15 | May 19 | May 25 |
| 32°F | Apr 13 | Apr 18 | Apr 21 | Apr 24 | Apr 28 | May 1 | May 4 | May 8 | May 14 |
| 28°F | Apr 1 | Apr 5 | Apr 9 | Apr 13 | Apr 16 | Apr 20 | Apr 23 | Apr 29 | May 4 |
| 24°F | Mar 21 | Mar 26 | Mar 30 | Apr 1 | Apr 4 | Apr 6 | Apr 9 | Apr 14 | Apr 20 |
| 20°F | Mar 9 | Mar 15 | Mar 18 | Mar 22 | Mar 25 | Mar 28 | Mar 31 | Apr 2 | Apr 8 |
| 16°F | Feb 28 | Mar 4 | Mar 8 | Mar 12 | Mar 15 | Mar 18 | Mar 22 | Mar 25 | Mar 30 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 20 | Sep 25 | Sep 29 | Oct 2 | Oct 5 | Oct 8 | Oct 11 | Oct 15 | Oct 20 |
| 32°F | Oct 1 | Oct 7 | Oct 12 | Oct 15 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 30 |
| 28°F | Oct 17 | Oct 21 | Oct 25 | Oct 28 | Oct 30 | Nov 1 | Nov 3 | Nov 7 | Nov 12 |
| 24°F | Nov 1 | Nov 2 | Nov 4 | Nov 6 | Nov 10 | Nov 13 | Nov 16 | Nov 20 | Nov 26 |
| 20°F | Nov 6 | Nov 10 | Nov 14 | Nov 17 | Nov 21 | Nov 24 | Nov 28 | Dec 2 | Dec 9 |
| 16°F | Nov 14 | Nov 19 | Nov 25 | Nov 29 | Dec 2 | Dec 5 | Dec 10 | Dec 16 | Dec 24 |
Freeze probabilities 1991–2020 at Warsaw, 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 46582 →Compare Warsaw with another place →
Weather by month in Warsaw
July is the warmest month at Warsaw, IN, averaging 84°F by day and 62°F at night; January is the coldest at 33°F and 17°F. A freezing night is all but certain in every month from October 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 41% of years.
Warmth for growing adds up to 3,023 growing degree days a year (base 50°F), fewer than at 89% of the 125 Indiana stations. 35% of them (1,052) have built up by the end of June, and July adds the most, 705. Precipitation totals 40.6 inches a year, most in May (4.9") and least in February (2.0"); May to September bring 53% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 33 | 17 | 2.6 | 100% | 28 | 1 |
| Feb | 37 | 19 | 2.0 | 100% | 25 | 2 |
| Mar | 48 | 28 | 2.2 | 100% | 22 | 27 |
| Apr | 61 | 38 | 4.1 | 99% | 8 | 107 |
| May | 72 | 49 | 4.9 | 41% | 1 | 331 |
| Jun | 81 | 58 | 4.7 | 0% | 0 | 585 |
| Jul | 84 | 62 | 4.4 | 0% | 0 | 705 |
| Aug | 82 | 60 | 4.5 | 0% | 0 | 645 |
| Sep | 76 | 52 | 2.9 | 9% | <1 | 432 |
| Oct | 64 | 42 | 3.2 | 92% | 5 | 160 |
| Nov | 50 | 31 | 2.7 | 100% | 17 | 26 |
| Dec | 38 | 22 | 2.4 | 100% | 26 | 3 |
Monthly normals 1991–2020 at Warsaw, IN (815 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, Northern Indiana WFO, IN, 8 miles northeast of Warsaw, has a last frost 4 days earlier (April 24), a first frost 6 days later (October 24), a season 12 days longer.
When it snows in Warsaw, Indiana
The first measurable snow (0.1 inch or more) in Warsaw usually arrives around December 7, and the last of the season around March 12. Those are the middle dates across the winters of 1991–2020 at Warsaw, IN, 2.8 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 47 days after the last snow.
Planting calendar for 46582
| When | What to do |
|---|---|
| February 17 – March 3 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 3 – March 17 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 31 – April 14 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 28 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 26 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 4 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 18 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 46582 is 3 miles from Warsaw, IN, which stands at 815 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 6 other ZIP codes share the station; its figures are presented in full for 46580 (Warsaw). The 2023 USDA Plant Hardiness Zone Map lists ZIP 46582 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.