The official National Weather Service forecast for Agar — 44.8383°N, 100.0746°W, 65.7 miles from I-90.
| Sully County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 27 | 32 | 44 | 58 | 69 | 80 | 87 | 85 | 77 | 60 | 45 | 31 | 58 |
| Avg low °F | 7 | 10 | 21 | 31 | 43 | 54 | 60 | 58 | 49 | 35 | 22 | 11 | 33 |
| Precip in | 0.4 | 0.5 | 0.8 | 1.9 | 3.0 | 3.2 | 2.4 | 2.4 | 1.8 | 1.6 | 0.5 | 0.5 | 19.0 |
1996–2025 normals for Sully County — the climate division Agar sits in. All-time county record high 111.6°F (2006-07-16); record low -35.2°F (1994-02-09). Source: NOAA / National Weather Service.