Merrillville, IN Weather & Growing Conditions
Overnight
63°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms. Cloudy, with a low around 63. East southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 63°F | Chance Showers And Thunderstorms | 10 mph ESE | 41% |
| Saturday | 78°F | Showers And Thunderstorms Likely | 5 to 10 mph SE | 97% |
| Saturday Night | 64°F | Showers And Thunderstorms Likely then Showers And Thunderstorms | 5 mph SSE | 89% |
| Sunday | 71°F | Showers And Thunderstorms Likely | 5 to 15 mph N | 62% |
| Sunday Night | 54°F | Chance Showers And Thunderstorms | 10 to 15 mph NE | 39% |
| Monday | 65°F | Chance Rain Showers | 10 to 15 mph NE | 39% |
| Monday Night | 51°F | Slight Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 22% |
| Tuesday | 64°F | Slight Chance Rain Showers | 10 to 15 mph NE | 17% |
| Tuesday Night | 52°F | Slight Chance Rain Showers then Mostly Cloudy | 5 to 10 mph NE | 17% |
| Wednesday | 65°F | Partly Sunny | 5 to 10 mph NNE | 9% |
| Wednesday Night | 52°F | Mostly Cloudy | 5 to 10 mph NNE | 6% |
| Thursday | 67°F | Partly Sunny | 5 to 10 mph NNE | 4% |
| Thursday Night | 52°F | Mostly Cloudy | 5 mph NNE | 4% |
| Friday | 70°F | Mostly Sunny | 5 to 10 mph NNE | 3% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Merrillville, IN
Last spring frost
Apr 22
First fall frost
Oct 25
Growing season
185 days
Hardiness zone
6a
Explore more for Merrillville, IN: full frost dates · planting calendar · Indiana frost dates
Climate data from the nearest NOAA station, Valparaiso Wtr Wks, In (15.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.