Harman US

Niantic, IL Weather & Growing Conditions

This Afternoon
88°F
Slight Chance Rain Showers
A slight chance of rain showers after 4pm. Mostly cloudy, with a high near 88. West southwest wind around 6 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.

7-day forecast

WhenTempForecastWindPrecip
This Afternoon 88°F Slight Chance Rain Showers 6 mph WSW 19%
Tonight 69°F Mostly Cloudy 6 mph S 10%
Sunday 84°F Slight Chance Rain Showers then Chance Showers And Thunderstorms 5 to 12 mph N 32%
Sunday Night 60°F Chance Showers And Thunderstorms 13 mph NE 52%
Monday 71°F Showers And Thunderstorms Likely 9 to 15 mph ENE 65%
Monday Night 55°F Chance Rain Showers 9 to 14 mph ENE 45%
Tuesday 68°F Chance Rain Showers 14 mph NE 45%
Tuesday Night 52°F Mostly Cloudy 6 to 14 mph NNE 9%
Wednesday 69°F Partly Sunny 8 to 12 mph NNE 2%
Wednesday Night 54°F Partly Cloudy 3 to 10 mph NNE 0%
Thursday 73°F Partly Sunny 5 to 8 mph NNE 1%
Thursday Night 56°F Mostly Cloudy 2 to 7 mph NNE 1%
Friday 76°F Partly Sunny 3 to 8 mph NE 5%
Friday Night 55°F Partly Cloudy 3 to 8 mph NE 5%

Forecast source: National Weather Service (api.weather.gov). Updated through the day.

Growing snapshot for Niantic, IL

Last spring frost
Apr 14
First fall frost
Oct 24
Growing season
192 days
Hardiness zone
6a

Explore more for Niantic, IL: full frost dates · planting calendar · Illinois frost dates

Climate data from the nearest NOAA station, Decatur Wtp, Il (11 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.