Keystone, IA Weather & Growing Conditions

Local forecast, frost dates, hardiness zone and planting guidance for Keystone, a city in Benton County, Iowa.

Overnight

66°F

Patchy Fog

Patchy fog and occasional showers and thunderstorms. Cloudy, with a low around 66. Southeast wind around 5 mph. Chance of precipitation is 80%. New rainfall amounts between a quarter and half of an inch possible.

7-day forecast for Keystone

When	Temp	Forecast	Wind	Precip
Overnight	66°F	Patchy Fog	5 mph SE	75%
Saturday	80°F	Patchy Fog then Showers And Thunderstorms Likely	5 to 10 mph S	98%
Saturday Night	61°F	Showers And Thunderstorms Likely	5 to 10 mph N	67%
Sunday	67°F	Rain Showers Likely	10 to 15 mph NE	59%
Sunday Night	55°F	Chance Rain Showers	10 to 15 mph NE	47%
Monday	63°F	Chance Rain Showers	10 to 15 mph NE	47%
Monday Night	50°F	Chance Rain Showers	10 mph NE	36%
Tuesday	61°F	Chance Rain Showers then Partly Sunny	10 mph NE	27%
Tuesday Night	46°F	Mostly Clear	5 mph NE	4%
Wednesday	66°F	Sunny	5 mph NE	0%
Wednesday Night	50°F	Partly Cloudy	0 to 5 mph NE	3%
Thursday	67°F	Partly Sunny	5 mph E	8%
Thursday Night	53°F	Partly Cloudy	0 to 5 mph E	6%
Friday	69°F	Mostly Sunny	5 mph E	6%

Forecast source: National Weather Service (api.weather.gov) for Keystone (41.999, -92.198). Updated through the day.

Growing snapshot for Keystone

Last spring frost

Apr 28

First fall frost

Oct 10

Growing season

165 days

Hardiness zone

More local growing data for Keystone: nearby ZIP 52249 weather · frost dates · planting calendar · Iowa frost dates

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Climate data from the nearest NOAA station, Belle Plaine, Ia (9.7 mi from Keystone). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.