Smithtown Weather Forecast
- 73
- 91
Slight Chance Thunderstorms
- 67
- 84
Partly Sunny
- 72
- 85
Rain Showers Likely
- 68
- 85
Chance Thunderstorms
- 67
- 83
Partly Sunny
- 68
- 83
Partly Sunny
Today 17 Jul Northwest Suffolk
Mostly cloudy with a chance of Showers and Thunderstorms this Morning, then mostly sunny with a slight chance of Showers and Thunderstorms this afternoon. Highs in the lower 90s. Southwest Winds 10 to 15 Mph with Gusts up to 25 Mph. Chance of rain 40 percent. Heat index Values up to 101.
Tonight 17 Jul Northwest Suffolk
Mostly clear in the Evening, then becoming partly cloudy. Humid with Lows in the lower 70s. Southwest Winds 10 to 15 Mph, becoming west after midnight. Gusts up to 25 Mph.
Smithtown Temperature Statistics
July Temperature
Islip, Long Island Mac Arthur Airport (6.2 miles)
Lowest 5 July, 2025
64.7 °FAverage July
77.3 °FHighest 8 July, 2025
92.6 °F
Climate (2020–Present)
Islip, Long Island Mac Arthur Airport (6.2 miles)
Average Low 2020–2025
47.5 °FAverage 2020–2025
55.2 °FAverage High 2020–2025
63 °F