Sinai, SD Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sinai, a town in Brookings County, South Dakota.
This Afternoon
61°F
Cloudy
Cloudy, with a high near 61. North northeast wind around 10 mph.
7-day forecast for Sinai
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 61°F | Cloudy | 10 mph NNE | 3% |
| Tonight | 52°F | Patchy Fog then Cloudy | 10 mph NE | 6% |
| Sunday | 64°F | Mostly Cloudy | 15 mph ENE | 4% |
| Sunday Night | 48°F | Rain Showers Likely | 10 to 15 mph ENE | 68% |
| Monday | 58°F | Rain Showers Likely | 10 mph ENE | 68% |
| Monday Night | 43°F | Mostly Cloudy | 5 to 10 mph E | 6% |
| Tuesday | 63°F | Partly Sunny | 5 to 10 mph ESE | 2% |
| Tuesday Night | 44°F | Partly Cloudy | 5 to 10 mph SE | 1% |
| Wednesday | 64°F | Mostly Sunny | 10 to 15 mph SE | 8% |
| Wednesday Night | 50°F | Showers And Thunderstorms Likely | 10 to 15 mph SSE | 57% |
| Thursday | 68°F | Showers And Thunderstorms Likely | 10 to 15 mph SSE | 57% |
| Thursday Night | 53°F | Mostly Cloudy | 5 to 10 mph SE | 14% |
| Friday | 72°F | Mostly Cloudy | 5 to 15 mph SE | 13% |
| Friday Night | 56°F | Mostly Cloudy then Chance Rain Showers | 10 to 15 mph SSE | 26% |
Forecast source: National Weather Service (api.weather.gov) for Sinai (44.244, -97.044). Updated through the day.
Growing snapshot for Sinai
Last spring frost
May 3
First fall frost
Oct 2
Growing season
151 days
Hardiness zone
4b
More local growing data for Sinai: nearby ZIP 57061 weather · frost dates · planting calendar · South Dakota frost dates
Nearby towns & communities
Aurora
Brookings
Bruce
Bushnell
Elkton
Newdale Colony
Norfeld Colony
Rolland Colony
Spring Lake Colony
Volga
Ward
White
Climate data from the nearest NOAA station, Arlington 1 W, Sd (10.3 mi from Sinai). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 20, 2026.