Last and first frost dates in Indianapolis

When is the last frost in Indianapolis?

The last frost in Indianapolis usually comes around 14 April: that is the median of 2016–2025, so in about half of those years the last night at or below 0 °C came later. Hardy crops start before it and frost-tender ones only after it: in the table below arugula can go into open ground from 24 March, while corn waits until 21 April. The first autumn frost follows around 6 November, about 206 days later: harvest or cover frost-tender crops before then.

When to sow and plant

Planting out: a week after the last frost once the soil is warm enough for the crop; frost-hardy crops three weeks before it; an unheated greenhouse three weeks earlier. Seedlings are sown so they are ready on that day. Each window starts on the Greenly calendar date and ends on the last day that still leaves the crop’s days to harvest (from its card) before the average first autumn frost, plus six weeks of picking for crops harvested over weeks (tomatoes, peppers, aubergines, cucumbers, courgettes, pumpkins, watermelons, beans) — our rule; earlier in the window is safer.

What planting zone is Indianapolis?

The official USDA map (2023, 1991–2020 data) puts the centre of Indianapolis (ZIP 46207) in zone 6b. Zone 6b stands for an average coldest night of -5 to 0 °F (-20.6 to -17.8 °C), so perennials hardy to zone 6b or a colder zone should come through a typical winter here.

Check the official USDA map for Indianapolis: USDA Plant Hardiness Zone Map.

When the soil warms up in Indianapolis

The day the top 7 cm of soil first averages each temperature over a week, median of 2016–2025 (ERA5 via Open-Meteo). The soil reaches 10 °C 16 days before the last spring frost and 15 °C 20 days after it.

Frost dates near Indianapolis

Of the nearest cities on our list, the last spring frost ends earliest in Louisville (6 April) and latest in Fort Wayne (24 April).

Seeds, seedlings and markets in Indianapolis

Within 15 km of Indianapolis OpenStreetMap lists 9 garden centres, 1 farm-supply shop, 2 plant nurseries and 4 markets (collected 20 October 2026). The nearest garden centre to the city centre is Grounded Plant + Floral Co., 1 km away.

• Grounded Plant + Floral Co. — garden centre
  Mon–Sun 10:00–18:00 · 1 km
• Cisco Seeds — farm supply
  North Shortridge Road 602, 46219 Indianapolis · 10 km
• Viet Hua Food Market — market
  Madison Avenue 8031, 46227 Indianapolis · Mon–Sun 09:00–21:00 · 14 km
• Botanical Bar — garden centre
  North College Avenue 1103, 46202 Indianapolis · 2 km
• Binford Farmers Market — market
  Northview Way 6620, 46220 Indianapolis · May–Sept Sat 08:00–12:00 · 14 km · binford71.org
• Snakeroot Botanicals — garden centre
  Virginia Avenue 1052, 46203 Indianapolis · Mon–Sun 11:00–19:00 · 3 km

• Where to buy seeds and seedlings in Indianapolis
• Selling your own harvest in the United States

Places: © OpenStreetMap contributors, ODbL.

Weather in Indianapolis by month

Average weather in Indianapolis over 2016–2025: the warmest month is July. Months that average 20 °C or more by day: May–September (22.9–29.7 °C). Nights average below 0 °C in January (-5 °C), February (-3 °C) and December (-2.1 °C). About 1140 mm of rain falls in a year, on 128 days; March is the wettest month (126 mm) and November the driest (72 mm).

Average of the daily highs and lows, rain per month and days with at least 1 mm (ERA5 via Open-Meteo, the same grid cell as the frost dates).

Planted in autumn

From a month before the first autumn frost, so the roots grow before winter, to the late-planting limit on each crop’s page (about two weeks before the ground freezes, by ten years of weather).