The official National Weather Service forecast for Eureka — 45.7694°N, 99.6196°W, 127.2 miles from I-29.
| McPherson County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 22 | 26 | 39 | 54 | 67 | 77 | 83 | 81 | 73 | 57 | 40 | 26 | 54 |
| Avg low °F | 4 | 6 | 18 | 30 | 42 | 54 | 59 | 56 | 47 | 34 | 20 | 9 | 32 |
| Precip in | 0.4 | 0.5 | 0.9 | 1.8 | 3.1 | 3.3 | 2.8 | 2.5 | 2.2 | 1.6 | 0.6 | 0.7 | 20.4 |
1996–2025 normals for McPherson County — the climate division Eureka sits in. All-time county record high 108.3°F (1973-07-12); record low -39.1°F (1967-12-31). Source: NOAA / National Weather Service.