Merrillville, IN Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Merrillville, a town in Lake County, Indiana.
Overnight
61°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms after 3am. Mostly cloudy, with a low around 61. East southeast wind around 10 mph, with gusts as high as 20 mph. Chance of precipitation is 30%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast for Merrillville
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 61°F | Chance Showers And Thunderstorms | 10 mph ESE | 34% |
| Saturday | 78°F | Showers And Thunderstorms Likely | 5 to 10 mph SE | 80% |
| Saturday Night | 66°F | Showers And Thunderstorms Likely | 5 mph SSW | 81% |
| Sunday | 70°F | Showers And Thunderstorms | 5 to 15 mph NNE | 81% |
| Sunday Night | 54°F | Rain Showers Likely | 10 to 15 mph NE | 66% |
| Monday | 65°F | Showers And Thunderstorms Likely | 10 to 15 mph ENE | 57% |
| Monday Night | 51°F | Chance Rain Showers | 10 to 15 mph NE | 35% |
| Tuesday | 64°F | Slight Chance Rain Showers | 10 mph NE | 18% |
| Tuesday Night | 51°F | Slight Chance Rain Showers | 5 to 10 mph NE | 18% |
| Wednesday | 66°F | Slight Chance Rain Showers then Partly Sunny | 5 to 10 mph NNE | 15% |
| Wednesday Night | 52°F | Mostly Cloudy | 5 to 10 mph NNE | 6% |
| Thursday | 68°F | Partly Sunny | 5 to 10 mph NNE | 4% |
| Thursday Night | 53°F | Mostly Cloudy | 0 to 5 mph NNE | 4% |
| Friday | 70°F | Mostly Sunny | 0 to 5 mph NNE | 4% |
Forecast source: National Weather Service (api.weather.gov) for Merrillville (41.473, -87.318). Updated through the day.
Growing snapshot for Merrillville
Last spring frost
Apr 22
First fall frost
Oct 25
Growing season
185 days
Hardiness zone
6a
More local growing data for Merrillville: nearby ZIP 46410 weather · frost dates · planting calendar · Indiana frost dates
Nearby towns & communities
Cedar Lake
Crown Point
Dyer
East Chicago
Gary
Griffith
Hammond
Highland
Hobart
Lake Dalecarlia
Lake Station
Leroy
Lowell
Munster
New Chicago
Ross
Schererville
Schneider
Shelby
St. John
Whiting
Winfield
Climate data from the nearest NOAA station, Valparaiso Wtr Wks, In (15.5 mi from Merrillville). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.