Roslyn, SD Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Roslyn, a town in Day County, South Dakota.
Tonight
54°F
Areas Of Drizzle
Areas of drizzle and areas of fog before 1am, then areas of fog and patchy drizzle. Cloudy. Low around 54, with temperatures rising to around 57 overnight. East wind 7 to 14 mph, with gusts as high as 28 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Roslyn
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 54°F | Areas Of Drizzle | 7 to 14 mph E | 44% |
| Saturday | 63°F | Areas Of Fog | 8 to 12 mph NE | 4% |
| Saturday Night | 52°F | Mostly Cloudy | 10 mph NE | 11% |
| Sunday | 62°F | Cloudy | 13 mph ENE | 6% |
| Sunday Night | 50°F | Chance Rain Showers | 7 to 10 mph E | 34% |
| Monday | 60°F | Chance Rain Showers then Mostly Cloudy | 9 mph E | 34% |
| Monday Night | 47°F | Mostly Cloudy | 7 mph ESE | 4% |
| Tuesday | 64°F | Mostly Sunny | 7 to 12 mph SE | 2% |
| Tuesday Night | 49°F | Partly Cloudy | 10 mph SSE | 8% |
| Wednesday | 66°F | Partly Sunny | 10 to 14 mph SSE | 12% |
| Wednesday Night | 53°F | Chance Rain Showers | 10 mph SSE | 26% |
| Thursday | 69°F | Chance Rain Showers then Partly Sunny | 9 mph S | 26% |
| Thursday Night | 54°F | Partly Cloudy | 7 mph SSE | 12% |
| Friday | 70°F | Partly Sunny | 8 to 13 mph SSE | 12% |
Forecast source: National Weather Service (api.weather.gov) for Roslyn (45.497, -97.493). Updated through the day.
Growing snapshot for Roslyn
Last spring frost
May 2
First fall frost
Oct 9
Growing season
160 days
Hardiness zone
4b
More local growing data for Roslyn: nearby ZIP 57261 weather · frost dates · planting calendar · South Dakota frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Roy Lake, Sd (11.7 mi from Roslyn). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.