Frost Dates for 46011 — Anderson, Indiana

Half of springs at Anderson Sewage Plt, IN see their last 32°F night by April 19; only one in ten is past it by April 3, and one in ten still has one after May 5. Planting tender crops after April 25 leaves a 30% risk of a frost on them, after April 30 20%, and after May 5 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 23 in half of years, as early as October 7 one year in ten, and holds off past November 6 one year in ten. A hard freeze of 28°F follows 11 days later, around November 3; in spring the one-in-ten date for 28°F is April 25, 10 days before the 32°F one. The freeze-free season lasts 186 days in a typical year, longer than at 62% of the 125 Indiana stations; it reaches 208 days one year in ten and falls short of 162 one year in ten. On average 112 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 April 30, and return around October 13. Severe cold of 16°F or below comes every winter, usually between December 8 and March 5.

July is the warmest month at Anderson Sewage Plt, IN, averaging 84°F by day and 65°F at night; January is the coldest at 35°F and 21°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 18% of years.

Warmth for growing adds up to 3,464 growing degree days a year (base 50°F), more than at 57% of the 125 Indiana stations. 36% of them (1,259) have built up by the end of June, and July adds the most, 753. Precipitation totals 43.8 inches a year, most in June (5.2") and least in February (2.5"); May to September bring 47% of it.

The nearest other station, Elwood, IN, 13 miles northwest of Anderson, has a last frost 5 days later (April 24), a first frost 5 days earlier (October 18), a season 11 days shorter.

The first measurable snow (0.1 inch or more) in Anderson usually arrives around December 8, and the last of the season around March 11. Those are the middle dates across the winters of 1991–2020 at Anderson Sewage Plt, IN, 1.1 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 39 days after the last snow.

ZIP 46011 is 1 mile from Anderson Sewage Plt, IN, which stands at 841 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 10 other ZIP codes share the station; its figures are presented in full for 46012 (Anderson). The 2023 USDA Plant Hardiness Zone Map lists ZIP 46011 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.