Sinai, SD Weather & Growing Conditions
Tonight
57°F
Areas Of Fog
Areas of fog after 10pm. Cloudy, with a low around 57. Northeast wind 5 to 10 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 57°F | Areas Of Fog | 5 to 10 mph NE | 11% |
| Saturday | 64°F | Areas Of Fog then Cloudy | 10 to 15 mph NNE | 11% |
| Saturday Night | 53°F | Mostly Cloudy | 10 to 15 mph NE | 2% |
| Sunday | 63°F | Mostly Cloudy then Slight Chance Rain Showers | 15 mph NE | 18% |
| Sunday Night | 50°F | Chance Rain Showers | 10 to 15 mph ENE | 50% |
| Monday | 60°F | Chance Rain Showers | 10 to 15 mph E | 50% |
| Monday Night | 46°F | Mostly Cloudy | 5 to 10 mph E | 9% |
| Tuesday | 64°F | Partly Sunny | 5 to 10 mph ESE | 2% |
| Tuesday Night | 47°F | Partly Cloudy | 5 to 10 mph SE | 4% |
| Wednesday | 66°F | Partly Sunny | 10 to 15 mph SSE | 11% |
| Wednesday Night | 51°F | Chance Rain Showers | 10 mph SSE | 34% |
| Thursday | 67°F | Chance Rain Showers | 10 mph SSE | 34% |
| Thursday Night | 53°F | Mostly Cloudy | 5 mph SSE | 11% |
| Friday | 69°F | Partly Sunny | 10 to 15 mph SE | 11% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Sinai, SD
Last spring frost
May 3
First fall frost
Oct 2
Growing season
151 days
Hardiness zone
4b
Explore more for Sinai, SD: full frost dates · planting calendar · South Dakota frost dates
Climate data from the nearest NOAA station, Arlington 1 W, Sd (10.3 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.