Merrillville Weather Forecast
- 55
- 68
Chance Rain Showers
- 52
- 64
Cloudy
- 52
- 64
Mostly Cloudy
- 52
- 65
Mostly Cloudy
- 52
- 67
Mostly Cloudy
- 51
- 68
Partly Sunny
- 53
- 72
Mostly Cloudy
Today 20 Sep Lake
Mostly cloudy. Highs in the mid 70s.
Tonight 20 Sep Lake
Cloudy. Areas of drizzle late in the Evening, then a chance of Showers after midnight. Lows in the mid 50s. Northeast Winds 10 to 15 Mph. Gusts up to 25 Mph late in the evening. Chance of precipitation 30 percent.
Merrillville Temperature Statistics
September Temperature
Gary Regional Airport (9.3 miles)
Lowest 14 September, 2026
51.8 °FAverage September
73.9 °FHighest 2 September, 2026
98.6 °F
Climate (2021–2026)
Gary Regional Airport (9.3 miles)
Average Low 2021–2026
44 °FAverage 2021–2026
51.8 °FAverage High 2021–2026
61.4 °F