Olney, IL
Climate overview — based on NOAA 1991-2020 normals from OLNEY 2S, IL US.
Year-round temperatures (°F)
Climate summary
Olney has an annual average temperature of 54.2°F with about 48.8 inches of precipitation per year and 10.5 inches of snow. The warmest month is July (average high 86.8°F), and the coldest is January (average low 20.8°F). May is typically the wettest month (5.60 in) and February the driest (2.57 in). Snow typically falls from November through March.
Best time to visit Olney
Full guide →Climate change signal
All-time records →18 of 366 (4.9%) of Olney's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 1890s | 10 | |
| 1900s | 35 | |
| 1910s | 43 | |
| 1920s | 41 | |
| 1930s | 77 | |
| 1940s | 40 | |
| 1950s | 36 | |
| 1960s | 13 | |
| 1970s | 13 | |
| 1980s | 14 | |
| 1990s | 9 | |
| 2000s | 8 | |
| 2010s | 16 | |
| 2020s | 11 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 37.8°F | 20.8°F | 29.3°F | 3.52 in | 3.6 in | 11 |
| February | 42.7°F | 23.9°F | 33.3°F | 2.57 in | 2.6 in | 9 |
| March | 53.4°F | 32.3°F | 42.9°F | 4.21 in | 1.1 in | 12 |
| April | 65.6°F | 42.7°F | 54.2°F | 5.02 in | — | 11 |
| May | 75.1°F | 53.3°F | 64.2°F | 5.60 in | — | 13 |
| June | 84.1°F | 62.4°F | 73.2°F | 4.79 in | — | 11 |
| July | 86.8°F | 65.6°F | 76.2°F | 4.96 in | — | 9 |
| August | 85.8°F | 63.8°F | 74.8°F | 3.19 in | — | 8 |
| September | 80.4°F | 55.8°F | 68.1°F | 3.31 in | — | 8 |
| October | 68.5°F | 44.3°F | 56.4°F | 3.83 in | — | 9 |
| November | 53.9°F | 33.5°F | 43.7°F | 4.26 in | 0.5 in | 10 |
| December | 42.3°F | 25.7°F | 34.0°F | 3.50 in | 2.7 in | 11 |
Climate twins of Olney
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).