Flat Rock, IL
Climate overview — based on NOAA 1991-2020 normals from PALESTINE, IL US.
Year-round temperatures (°F)
Climate summary
Flat Rock has an annual average temperature of 55.1°F with about 46.3 inches of precipitation per year and 11.6 inches of snow. The warmest month is July (average high 86.5°F), and the coldest is January (average low 22.8°F). April is typically the wettest month (5.06 in) and February the driest (2.63 in). Snow typically falls from November through March.
Best time to visit Flat Rock
Full guide →Climate change signal
All-time records →9 of 366 (2.5%) of Flat Rock'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 | 15 | |
| 1900s | 20 | |
| 1910s | 27 | |
| 1920s | 33 | |
| 1930s | 74 | |
| 1940s | 26 | |
| 1950s | 61 | |
| 1960s | 20 | |
| 1970s | 9 | |
| 1980s | 28 | |
| 1990s | 15 | |
| 2000s | 25 | |
| 2010s | 13 | |
| 2020s | 0 |
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 | 38.4°F | 22.8°F | 30.6°F | 3.48 in | 4.3 in | 9 |
| February | 43.5°F | 26.4°F | 35.0°F | 2.63 in | 2.2 in | 8 |
| March | 54.4°F | 34.7°F | 44.6°F | 3.58 in | 1.1 in | 10 |
| April | 66.6°F | 44.5°F | 55.6°F | 5.06 in | — | 11 |
| May | 76.1°F | 55.4°F | 65.7°F | 4.91 in | — | 11 |
| June | 84.1°F | 63.4°F | 73.8°F | 4.88 in | — | 10 |
| July | 86.5°F | 66.3°F | 76.4°F | 4.23 in | — | 9 |
| August | 85.7°F | 64.0°F | 74.8°F | 3.53 in | — | 7 |
| September | 80.4°F | 56.2°F | 68.3°F | 3.58 in | — | 7 |
| October | 68.4°F | 45.6°F | 57.0°F | 3.73 in | 0.1 in | 8 |
| November | 53.6°F | 34.8°F | 44.2°F | 3.63 in | 0.5 in | 9 |
| December | 42.1°F | 27.5°F | 34.8°F | 3.06 in | 3.4 in | 10 |
Climate twins of Flat Rock
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).